Recent Submissions

  • Risk of Subsequent Cardiovascular Events Among Medicare Beneficiaries Diagnosed with Obstructive Sleep Apnea and Treated with Continuous Positive Airway Pressure

    Ismail, M. Doyinsola; Wickwire, Emerson M.; Scharf, Steven M., 1946-; Srivastava, Mukta C.; Somers, Vivend K.; Albrecht, Jennifer S. (2020)
    Introduction: Obstructive sleep apnea (OSA) is associated with increased risk of cardiovascular disease (CVD) but it remains uncertain whether treatment with Continuous Airway Pressure (CPAP) can prevent major cardiovascular (CV) events, especially among older adults. Research Objective: To estimate the incidence of CV events among older Medicare beneficiaries, with and without pre-existing CVD, who initiated CPAP therapy following OSA diagnosis.
  • Development of the Drude Polarizable Force Field for Small Molecules Drude General Force Field (DGenff)

    Chatterjee, Payal; MacKerell, Alexander D., Jr. (2020)
    The classical Drude oscillator polarizable force field offers an explicit treatment of induced electronic polarization presently not addressed in the commonly used additive force fields. Such an empirical approach leads to an improved and more accurate representation of electrostatic interactions in Molecular Mechanics and Molecular Dynamics (MD) simulations. The Drude Polarizable Force Field presently include topologies and parameters for biomolecules such as proteins, lipids, carbohydrates, and nucleic acids along with a limited set of small molecules. The present research is an effort to expand the existing Drude-oscillator based polarizable force field of CHARMM for general small drug like molecules – Drude General Force Field (DGenFF). A thorough development of such a force field will allow users to use polarizable force fields for drug design and other chemical fields.
  • Designing Specific Inhibitors to Target S100B in Melanoma

    Vera-Rodriguez, Darex J.; Young, Brianna; Spriggs, Shardell; Yu, Wenbo; Wilder, Paul T.; MacKerell, Alexander D., Jr.; Weber, David J., Ph.D. (2020)
    Malignant melanoma (MM) is defined as the most dangerous form of skin cancer, causing a large majority of skin cancer deaths. Previous studies demonstrate S100B as a tumor marker in MM, a protein that interacts with the tumor suppressor p53, inhibiting p53 function. With the goal of blocking this interaction, three binding sites on S100B for small molecules have been identified. However, developing drugs specific for S100B over other S100-family members remains a challenge. This project aims to identify S100B-specific small molecule inhibitors and understand the basis of their specificity over other S100 family members, specifically S100A1. A 2D-[1H,15N] NMR HSQC of S100B bound to a non-specific fragment showed multiple chemical shifts perturbations (CSPs) including residues A9, L10, F43, L40, F73, and C84. Interestingly, fewer and less pronounced CSPs were observed for a S100B-specific fragment. Site-Identified Ligand Competitive Saturation (SILCS) molecular dynamics (MD) simulations were performed to determine potential S100B binding sites that could explain the CSPs. Results show a strong hydrophobic pocket at low Grid Free Energy (GFE) levels comprised by the residues that showed CSPs for compounds that bind S100B. FDA-approved compounds were tested using SILCS-Monte Carlo (MC) to determine ligand binding poses at this pocket. Specific compounds were targeted with strong hydrophobic interactions and hydrogen bonds at low Ligand GFE (GFE). These data provide important information relevant to developing S100B-specific drugs to treat MM.
  • Graduate Research Conference 2020

    University of Maryland, Baltimore. Graduate Student Association (2020-03-06)
  • Graduate Research Conference 2019

    University of Maryland, Baltimore. Graduate Student Association (2019-03-15)
  • Modulation of Pathophysiological Processes of Autoimmune Arthritis by Indole-3-Acetic acid and Indole-3-Aldehyde

    Langan, David; Meka, Rakeshchandra R.; Moudgil, Kamal (2020-03)
    Rheumatoid arthritis (RA) afflicts 0.5-1% of US adults, making it one of most common autoimmune diseases. Clinical RA is characterized by swelling of the joints of both extremities. Environmental factors, including diet and microbiome dysbiosis, are disease-modifying factors for RA. Indole-3-acetic acid (I3AA) and indole-3-aldehyde (IAld) are derived from both the diet and gut microbiota. We hypothesized that I3AA and IAld, ligands for the aryl hydrocarbon receptor (AhR), regulate critical AhR-dependent arthritisrelated processes, namely production of pro-inflammatory cytokines, angiogenesis (new blood vessel formation), and osteoclastogenesis (bone resorption). We tested this using in vitro models of these 3 processes. Both I3AA and IAld inhibited IL-1β and IL-6 expression (by RT-qPCR), in RAW264.7 (RAW) cells treated with M. tuberculosis H37Ra sonicate (H37Ra) or LPS compared with vehicle control. Additionally, I3AA-treated RAW cells cultured in the presence of receptor activated nuclear-factor kappa beta (RANKL) formed fewer osteoclasts along with reduced expression of tartrate-acid phosphatase (TRAP) and cathepsin-K expression (CatK) (by RTqPCR), compared to vehicle-treated cells; whereas, IAld-treated cells formed more osteoclast along with more TRAP and CatK expression. Human umbilical vein endothelial cell (HUVEC) tube formation (Matrigel assay), indicative of angiogenesis, was inhibited by I3AA, while IAld had minimal or no effect. These preliminary results suggest that I3AA and IAld are capable of modulating key RA-disease processes. We plan to examine the effect of AhR inhibitors on these processes, and to assess whether I3AA and/or IAld can confer protection against arthritis in a rat model of RA.
  • ADHD Coaching Communication Modalities: An Exploratory Mixed Methods Study

    Ahmann, Elizabeth; Saviet, Micah (2019)
    Background. Telephone is the most frequently used communication modality for coaching sessions in the U.S.; a combination of in-person and telephone coaching is also common. Coaching in person or by telephone, videoconference, or a combination of methods demonstrates positive outcomes. Studies comparing outcomes of coaching inperson with telephone or videoconference suggest varied results. To date, no study has specifically examined communication modalities in coaching for individuals having attention deficit hyperactivity disorder (ADHD). Purpose. This mixed methods exploratory study: • Reviews extant literature on ADHD coaching outcomes to identify coaching modalities used • Surveys ADHD coaches to explore (a) the frequency of use and perceived efficacy of varied modalities and (b) coaches' views of benefits and drawbacks of each
  • Graduate Research Conference 1996

    University of Maryland, Baltimore. University of Maryland Baltimore County Graduate Student Association (1996-05-01)
    The Graduate Student Research Day (GSRD) is a one-day conference that provides graduate students from the University of Maryland Baltimore County (UMBC) and the University of Maryland at Baltimore (UMAB) the opportunity to present results of their ongoing research to peers, faculty members, the University of Maryland community at large, and other interested parties. Co-sponsored by theUMBC and UMAB Graduate Student Associations (GSA), the GSRD event provides a forum for the exchange of information and ideas. With 130 scheduled presentations, GSRD 96 has the highest level of participation in the history of this event.
  • Graduate Research Conference 1993

    University of Maryland, Baltimore. Graduate Student Association (1993-05-05)
    This is the program and collection of abstracts for poster and oral presentations for the 15th Annual GRC. This conference offers researchers, be they graduate students, professional students, or postdoctoral fellows, the opportunity to present their discoveries to a diverse audience. Our unique combination of research across various professional schools and disciplines allows basic scientists, informaticists, social scientists, nurses, and policy researchers to intermingle and discuss their research in an interdisciplinary setting.
  • Graduate Research Conference 1991

    University of Maryland, Baltimore. Graduate Student Association (1991-05-01)
    This is the program and collection of abstracts for poster and oral presentations for the 13th Annual GRC. This conference offers researchers, be they graduate students, professional students, or postdoctoral fellows, the opportunity to present their discoveries to a diverse audience. Our unique combination of research across various professional schools and disciplines allows basic scientists, informaticists, social scientists, nurses, and policy researchers to intermingle and discuss their research in an interdisciplinary setting.
  • Graduate Research Conference 1988

    University of Maryland, Baltimore. Univesity of Maryland Baltimore County. Graduate Student Association (1988-04-20)
    This is the program and collection of abstracts for poster and oral presentations for the 10th Annual GRC. This conference offers researchers, be they graduate students, professional students, or postdoctoral fellows, the opportunity to present their discoveries to a diverse audience. Our unique combination of research across various professional schools and disciplines allows basic scientists, informaticists, social scientists, nurses, and policy researchers to intermingle and discuss their research in an interdisciplinary setting.
  • Graduate Research Conference 2018

    University of Maryland, Baltimore. Graduate Student Association (2018-03-15)
  • Graduate Research Conference 2017

    University of Maryland, Baltimore. Graduate Student Association (2017-04-03)
  • Developing a 3D-Printed Peri-Implantium Based Plaque Assay (2016)

    Feldman, Steven G.; Kim, Jeffrey J. (2016-03-23)
    Objectives: Currently, there is no consensus of how to best maintain dental implants. With over 2 million dental implants placed annually, there is an urgent need for objective ways to measure plaque removal from peri-implant surfaces. Here, we developed a cost effective, fast and accurate way to measure the effectiveness of various oral hygiene products to maintain health of the implant and surrounding oral tissues using a 3D printer. Methods: Digitizations of dentoform teeth and jaws provided the basis for 3D-printed custom models. Simulated gingiva and genuine dental implants were incorporated to maximize clinical relevance. Fabricated model teeth were analyzed for consistency of cusp heights, inter-cusp distance and mass. Mass was remeasured following water immersion. An artificial plaque substrate (APS) was applied to 3D-printed and porcelain surfaces to ensure consistent performance. A standard by which toothbrush mediated APS removal from the interproximal and subgingival areas was developed, with varying brushing angle, force and toothbrush design. Results: The 3D-printed models had higher dimensional accuracy than the resolution of the 3D printer (X/Y<400μm, Z<100μm). Immersion in water yielded an increase in mass that was correlated linearly with time (r2 = .9365) and could be reversed upon desiccation. APS behaved similarly on the 3D-printed surface as porcelain. Conclusions: Lack of commercially available dentoforms with accurate dental implant anatomy limited the ability to simulate implant systems in vitro. However, the advent of low-priced commercial grade 3D printers enables individuals to create such models rapidly and at low cost. We developed highly accurate, anatomically correct, 3D-printed dental implant model systems, which mitigated flaws in extant designs and devised a high-throughput method for assessing in vitro plaque removal that is superior to existing methods. In the future, digital model files can be included in an electronic library for rapid manufacturing of identical models anywhere in the world.
  • Tissue Lipid Analysis via MALDI Imaging (MALDI-IMS)

    Feldman, Steven G.; Scott, Alison June; Ernst, Robert K. (2013-04-11)
    Mammalian tissue contains a complex array of lipids and membrane components. Analysis is typically accomplished by one of many histological methods, such as Hematoxylin and Eosin (H&E) stain, immunohistochemistry (IHC) and in situ hybridization (ISH). However, a limitation of most techniques is a requirement for prior knowledge of the targets of interest. Mass spectrometry (MS) coupled assays are useful for their inherent speed and accuracy. Hyphenated MS techniques, such as MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization-Time of Flight) have been developed for rapid analysis of complex biological samples. MALDI-TOF MS lends itself to tissue slices because it does not require pure samples and can offer de novo discovery of sample components. Here we show the coupling of this technique with histological staining for the investigation of lipids and their localization within mouse kidney tissue slices. This method is shown to be extensible through the incorporation of LIFT (MS/MS) wherein a specific peak of known molecular weight is exposed to a high energy laser which causes reliable and reproducible fragmentation based on bond energies within the molecule. As such, aspects of the target molecule from a class (eg phospholipids) down to side chains can be identified allowing the fullscale investigation of major tissue components. In a proof of concept study, pure standards of the major phospholipids phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were subjected to LIFT, to confirm structures. Subsequently, MALDI-IMS applied to tissue slices reveals abundant peaks in the range of predicted phospholipids. These results will be analyzed to confirm these tissue phospholipids. MALDI-TOF MS coupled with LIFT presents a novel way of looking at tissue without prior knowledge of its constituents as it allows for analysis in the absence of traditional reagents such as antibodies or nucleic acid probes.
  • Graduate Research Conference 2016

    University of Maryland, Baltimore. Graduate Student Association (2016-03-23)
  • The Effects of reactive and voluntary step training on balance recovery during lateral perturbation in individuals with chronic stroke

    Yang, Chieh-ling; Gray, Vicki L.; McCombe-Waller, Sandra; Rogers, Mark William (2016-04)
    Falls have been reported as high as 73% in community dwelling individuals following a stroke. Many falls happen while transferring weight laterally. To guard against loss of balance with this lateral weight transfer a reactive, protective step is commonly used to recover balance. Current rehabilitation practices mainly focus on intentional voluntary actions to improve balance control which may not carry-over to the development of protective stepping strategies to avoid a fall. Objective: The purpose of this study is to determine the effects of six weeks of reactive versus voluntary step training on balance recovery during lateral perturbations in individuals with chronic stroke
  • The Role of Residential Segregation in Disparity Research: A Case Example of ADHD Diagnosis and Treatment

    Pennap, Dinci; Burcu, Mehmet; Safer, Daniel J.; Zito, Julie Magno (2015-08-24)

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