This study was conducted using a quantitative, non-experimental, correlation design to explore the relationships between student-patient encounters with Diabetes Mellitus and the scores on the Diabetes Mellitus OSCE during Family Medicine clerkship. The focus of the research was to explore relationships between various methods of competency measures of third-year medical students during their Family Medicine clerkship as they encountered patients diagnosed with Diabetes Mellitus (DM). A paradigm shift in medical education is taking place and driven by the Liaison Committee for Medical Education (LCME). These changes are fueled by the public outcry demanding verification of competency of our physicians. The study's focus is on the competency outcome measures from a new educational design, moving away from patient-centered education to competency-based, student-centered education and away from a norm-referenced assessment to a criterion-referenced assessment. Relevant literature on the need for competency-based medical education and various methods for implementation informed this study, including Miller (1990); Barman (2005); Barrows (1993), De Champlain, Margolis, Macmillan, and Klass (2001); Harden and Gleeson (1979); and Howley and Wilson (2004). More direct observation of student performance must be instituted with documentation of student clinical skills. Findings revealed no differences are seen in medical student competency acquisition during encounters of patients diagnosed with DM, in terms of cognitive, psychomotor, neck exam or affective measures, during the VCU SOM Family Medicine Clerkship. Significant differences are noted in the psychomotor subscale scores of the DM OSCE as the result of suburban clerkship site placement, as opposed to rural or urban sites. Finally, students at non-residencies see more patients with DM than at residency clerkship sites. Implications for further research were discussed focusing on 1) why differences were found only found in suburban clerkship sites; 2) the possibility that cultural competency understanding may play a role in these differences; 3) how do students learn about DM prior to the FM clerkship; 4) the possibility that the OSCE does not reflect community FM practice models.

As a novel therapy for neurodegenerative diseases, transplantation of multipotent mesenchymal stromal cells (MSCs) requires extensive optimization in animal models before being implemented in clinical trials. It is a goal of our laboratory to understand the mechanism of action of these cells and to improve their therapeutic efficacy. To address these goals, this study aims to optimize the cell dosage, cell type, administration route and timing, and/or donor age for stem cell therapy in two mouse models of demyelinating diseases: globoid cell leukodystrophy (GLD; Krabbe’s disease) and experimental autoimmune encephalomyelitis (EAE). GLD is a neurodegenerative lysosomal storage disease caused by the deficiency of galactocerebrosidase (GALC). Accumulation of toxic byproducts in myelin producing oligodendrocytes leads to the demyelination of neurons and increase in brain inflammation. The twitcher mouse model of GLD was used to test the therapeutic effects of MSCs after injection through intracerebroventricular (ICV) or intraperitoneal (IP) routes. Weekly MSC IP injections and single IP GALC-transduced MSC injections were performed. Other twitcher mouse cohorts received temporal vein (TV) or intracerebral (IC) injections of GALC-containing adeno-associated virus serotype 9 (AAV9-GALC) with or without IP MSC injections. All GLD affected mice treated with peripheral MSC and/or vector therapy had extended lifespans with improved motor function. The ameliorating effects of MSCs were related to their potent anti-apoptotic and anti-inflammatory effects on the peripheral and central nervous systems. These results indicate a promising future for peripheral administration of MSCs and vectors as non-invasive, adjunct therapies for patients affected with GLD. A similar study was performed using the EAE mouse model of multiple sclerosis (MS), which is a demyelinating disease due to an autoimmune reaction to myelin. The results demonstrated that biological age of the donor reduces the ability of MSCs to alleviate symptoms and improve pathology in the EAE mouse model. Upon transplantation, the young, but not old, MSCs provided neuroprotective effects through immunomodulation and remyelination in the central nervous system (CNS). The age-related therapeutic differences corroborate recent findings that biologic aging occurs in stem cells and highlight the potential need for allogeneic transplantation of MSCs in older MS patients. / acase@tulane.edu

Human Immunodeficiency Virus -1 infects CD4+ cells, and the subsequent loss of these cells cause Acquired Immune Deficiency Syndrome. Highly active antiretroviral therapy (HAART) is crucial to control viremia in the clinical management of AIDS/HIV infection; however, drug regimens are complex, expensive, and require life-long intervention with potential side effects. Current conventional anti-HIV drugs target different phases of the HIV life cycle and can be categorized as nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors, entry inhibitors (co-receptor antagonists and fusion inhibitors), and integrase inhibitors(II). Enfuvirtide (Fuzeon, or T-20) is the first fusion inhibitor approved by the FDA and has substantial side effects and drug delivery issues with most patients developing some local injection site reaction. The subcutaneous application of enfuvirtide and its short half-life, which requires twice daily administration, has disadvantages in patients who are already burdened by complex oral therapy. To overcome these drug issues, we propose an alternative method to administer the HIV-1 peptide fusion inhibitor C46. Stem cells can be a vehicle for delivering genes to specific tissues in the body and their therapeutic delivery systems are extensively used in cancer research. For many years, restoration of blood and immune system function has been used as a component in the care of cancer patients who have been treated with chemotherapeutic agents. Mesenchymal Stem Cells (MSCs) have been demonstrated as a delivery vehicle for gene therapy applications based on their ability to engraft and home to inflamed tissues. MSCs are multi-potent and have immunological function in several human diseases. To investigate MSCs immune suppressive ability in HIV infection system, we will evaluate the crosstalk between MSCs and HIV infection immune-modulatory network. / acase@tulane.edu

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Triple-negative breast cancer (TNBC) accounts for 15% of all diagnosed breast cancers nationally and affects African-American women 3 times more likely than any other ethnic group. Locally, African-American women in the New Orleans area see higher incidence of TNBC cases versus African-American women from the rest of the state of Louisiana, which represents an area of heightened public health interest for the metropolitan area. TNBC is a highly metastatic disease, and targeted therapies such as tamoxifen and herceptin are ineffective due to the lack of estrogen receptor (ER) and HER2/neu target expression in TNBC tumors. Chemotherapy remains the only effective drug therapy in TNBC cases. Evaluating new classes of drugs for clinical use against TNBC as well as furthering our understanding of underlying regulatory mechanisms in TNBC is a priority. Pan-deacetylase inhibitors (DACi), like panobinostat, have shown promise in clinical trials as therapies in other cancers. Pre-clinical data of panobinostat treatment in TNBC cell lines published by this lab has been positive so far, exhibiting a reduction in TNBC metastatic potential. DACi can alter multiple signaling pathways and are known to restore dysregulated microRNA (miRNA) expression patterns (miRnome) in cancers. MiRNA are a relatively new class of non-protein coding regulatory biomolecules that exhibit a variety of cancer-related properties, many still unknown in TNBC. Pan-DACi treatment combined with miRnome analysis in TNBC cell lines can be used to identify previously unknown miRNA cancer-related properties in TNBC. The specific aim of this project consists of using DACi treatment on TNBC cell lines in conjunction with miRnome analysis to identify previously undescribed anti-cancer miRNAs and elucidate their cancer-related properties in TNBC while uncovering affected cancer pathways, detecting miRNA targets, and revealing affected downstream components. Initial miRNA expression analysis of MDA-MB-231 TNBC cells treated with panobinostat or trichostatin A versus controls produced a list of potential anti-cancer miRNA candidates for further study. Among them, investigations into miR-203 and miR-335 produced unclear results as these were theorized to have anti-metastatic properties in TNBC yet enhanced cancer properties in our models and assays. Overexpression of mir-215 (a tumor suppressor in other cancers) unexpectedly enhanced tumor growth five fold in SCID mice xenografted with lentivirally-transduced MDA-MB-231 breast cancer cells stably overexpressing miR-215 (231/215+). Further qPCR analysis of 231/215+ cells uncovered upregulation of the breast cancer-associated lncRNA, HOTAIR; the breast cancer-associated miRNA, miR-196a; as well as the entire HOXC cluster in which they reside. This represents a previously unidentified regulatory mechanism of the HOXC cluster in humans. Additionally, miR-200b overexpression in MDA-MB-231 cells induced a change in cell morphology to an epithelial-like phenotype, reduced migration by 50%, and re-expressed the epithelial marker CDH1. This demonstrates a partial reversal of epithelial-mesenchymal transition (EMT), which indicates a reduction in metastatic potential by miR-200b overexpression in MDA-MB-231 cells. Additionally, these cells exhibited increased estrogen receptor alpha and related signaling pathways while also being susceptible to reduced proliferation with the anti-estrogen drug fulvestrant at high doses. Using pan-DACi treatment of TNBC cells to analyze changes in the miRnome for unknown cancer-related miRNA candidates suitable for further investigation in TNBC, we identified miR-215 overexpression in MDA-MB-231 cells as an oncogenic event that enhances tumor growth, cell proliferation, and HOXC cluster transcription while miR-200b is an anti-metastatic miRNA that partially reverses EMT and reduces fulvestrant resistance through re-expression of estrogen receptor signaling. / acase@tulane.edu

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MiR-17-92 is an oncogenic miRNA cluster implicated in the development of several human cancers; however, it remains unknown whether miR-17-92 cluster is able to regulate hepatobiliary carcinogenesis. This study was designed to investigate the biological functions and molecular mechanisms of miR-17-92 cluster in primary liver cancer.<br>In-situ hybridization and qRT-PCR analysis showed that miR-17-92 cluster is highly expressed in human cholangiocarcinoma cells compared to the non-neoplastic biliary epithelial cells. Forced overexpression of the miR-17-92 cluster or its members, miR-92a and miR-19a, in cultured human cholangiocarcinoma cells enhanced tumor cell proliferation, colony formation and invasiveness, in vitro. Overexpression of miR-17-92 cluster or miR-92a also enhanced cholangiocarcinoma growth in vivo in SCID hairless outbred mice. The tumor suppressor PTEN was identified as a bona fide target of both miR-92a and miR-19a in cholangiocarcinoma cells. Accordingly, overexpression of PTEN open reading frame protein (devoid of 3’UTR) prevented miR-92a- or miR-19a-induced cholangiocarcinoma cell growth. Microarray analysis revealed additional targets of miR-17-92 cluster in human cholangiocarcinoma cells, including APAF-1 and PRDM2. Moreover, we observed that the expression of miR-17-92 cluster is regulated by IL-6/Stat3, a key oncogenic signaling pathway pivotal in cholangiocarcinogenesis. Taken together, our findings in this study disclose a novel IL-6/Stat3 miR-17-92 cluster PTEN signaling axis that is crucial for cholangiocarcinogenesis and tumor progression.<br>We also found the miR-17-92 is highly expressed in tumor tissue compared to non-tumor adjacent tissue in hepatocellular carcinoma patient tissue. Forced overexpression of the miR-17-92 cluster in cultured human hepatocellular carcinoma cells enhanced tumor growth in vitro; on contrast, inhibition of miR-17-92 cluster inhibited cell growth. MiR-17-92 cluster promote diethylnitrosamine-induced hepatocarcinogenesis in liver-specific miR-17-92 cluster transgenic mice. Binding sequence and mice whole genome microarray analysis revealed about 300 possible targets. RNA-sequencing data analysis showed both individual miRNAs and the host gene of miR-17-92 cluster was highly expressed in hepatocellular carcinoma patients and had negative correlation with several genes (CREBL2, PRRG1, and NTN4), among which, CREBL2 may play an important role in the hepatocarcinogenesis. / acase@tulane.edu

There are not enough donor lungs available to meet the increasing demand for lung transplantation. To compound the problem, transplant recipients have a projected survival time of only 5.7 years despite life-long immunosuppression. An alternative approach for acquiring transplantable lungs and reducing post-operative complications may be possible through tissue engineering. Perfusion-decellularization generates natural, three-dimensional extracellular matrix (ECM) scaffolds of an organ that are apt for tissue engineering. Decellularization of the heart, lung, liver, kidney, and pancreas has been reported in animal models and from human tissue. Decellularization of fibrotic and emphysematic lungs indicated that this technique can efficiently remove cells from diseased tissue—a potential source of materials for engineering of transplantable lung tissue. Pulmonary hypertension (PHT) is a vascular disease characterized by increased pulmonary vascular resistance leading to right heart failure and death. Lungs damaged by PHT are unsuitable for transplantation; however, decellularization of these organs may provide scaffolds appropriate for ex vivo lung engineering. Monocrotaline-induced PHT (MCT-PHT) is a well-established model of this disease in rats closely resembling the clinical presentation of PHT in humans. Thus, decellularization and recellularization of hypertensive lungs was evaluated using the MCT-PHT model. Decellularization of control and MCT-PHT Sprague-Dawley rat lungs was accomplished by treating the lungs with Triton X-100, sodium deoxycholate (SDC), NaCl, and DNase. The resulting acellular matrices were extensively characterized by molecular, mechanical, and structural analyses revealing that decellularization was able to remove cells while leaving the ECM components and lung ultrastructure intact; however, the vasculature of MCT-PHT acellular lung scaffolds was narrower than control scaffolds—a hallmark of PHT. To evaluate the effect of narrowed vasculature on the use of hypertensive lungs for tissue engineering, an optimal vascular recellularization technique was developed. Gravity-based seeding of endothelial cells followed by bioreactor-based whole-organ culture resulted in efficient vascular recellularization of control lung scaffolds. However, this method led to heterogeneous re-endothelialization of the vasculature of MCT-PHT matrices suggesting that additional manipulation or optimization is required. / acase@tulane.edu

The active human retrotransposon L1 is the most prevalent human retroelement, constituting 17% of the mass of the human genome and contributing significantly to mutagenesis. L1 mutagenizes human genomes in a number of ways including insertional mutagenesis of itself and other retrotransposons, creating of DNA double strand breaks, and induction of non-allelic homologous recombination. Through these processes, the activity of L1 is responsible for approximately 0.5% of all new genetic diseases. All L1-derived mutagenesis stems from the activity of a small number of intact full-length L1 loci that remain capable of mobilization. A smaller subset of these active L1s are called hot L1s and are responsible for the vast majority of all L1 activity. Hot L1s are polymorphic in the population and represent evolutionarily recent L1 insertion events. Here, we show that potentially active full length L1 elements are more prevalent in individual genomes than previously believed. We find that the typical individual likely harbors approximately 60 active and 50 hot L1s. However, we also find that there is significant variation between individuals in numbers of potentially active L1s. As a result, the mutagenic burden associated with L1 likely varies between individuals. / acase@tulane.edu

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