Medicine and Health Sciences Commons^™

Pathogenicity And Impact Of Hla Class I Alleles In Aplastic Anemia Patients Of Different Ethnicities, Timothy S Olson, Benjamin F Frost, Jamie L Duke, Marian Dribus, Hongbo M Xie, Zachary D Prudowsky, Elissa Furutani, Jonas Gudera, Yash B Shah, Deborah Ferriola, Amalia Dinou, Ioanna Pagkrati, Soyoung Kim, Yixi Xu, Meilun He, Shannon Zheng, Sally Nijim, Ping Lin, Chong Xu, Taizo A Nakano, Joseph H Oved, Beatriz M Carreno, Yung-Tsi Bolon, Shahinaz M Gadalla, Steven Ge Marsh, Sophie Paczesny, Stephanie J Lee, Dimitrios S Monos, Akiko Shimamura, Alison A Bertuch, Loren Gragert, Stephen R Spellman, Daria V Babushok

Department of Medicine Faculty Papers

Acquired aplastic anemia (AA) is caused by autoreactive T cell-mediated destruction of early hematopoietic cells. Somatic loss of human leukocyte antigen (HLA) class I alleles was identified as a mechanism of immune escape in surviving hematopoietic cells of some patients with AA. However, pathogenicity, structural characteristics, and clinical impact of specific HLA alleles in AA remain poorly understood. Here, we evaluated somatic HLA loss in 505 patients with AA from 2 multi-institutional cohorts. Using a combination of HLA mutation frequencies, peptide-binding structures, and association with AA in an independent cohort of 6,323 patients from the National Marrow Donor Program, we …

A Critical Review Of Medication Adherence In Hypertension: Barriers And Facilitators Clinicians Should Consider, Seyed Mehrdad Hamrahian, Omar H. Maarouf, Tibor Fülöp

Department of Medicine Faculty Papers

Hypertension is a global public health problem, and its prevalence is increasing worldwide. Impacting all human societies and socioeconomic strata, it remains the major modifiable risk factor for global burden of cardiovascular disease all-cause mortality and the leading cause of loss of disability-adjusted life years. Despite increased awareness, the rate of blood pressure control remains unsatisfactory, particularly in low-to middle-income countries. Apparent treatment-resistant hypertension is associated with worse adverse health outcomes. It includes both true resistant and pseudo-resistant hypertension, which requires out-of-office blood pressure monitoring to exclude white-coat effect and confirmation of adherence to the agreed recommended antihypertensive therapy. The …

D121 Located Within The Dry Motif Of P2y12 Is Essential For P2y12-Mediated Platelet Function., Carol Dangelmaier, Benjamin Mauri, Akruti Patel, Satya P Kunapuli, John C Kostyak

Department of Medicine Faculty Papers

Platelets are anucleate cells that mediate hemostasis. This occurs via a primary signal that is reinforced by secreted products such as ADP that bind purinergic receptors (P2Y1 and P2Y12) on the platelet surface. We recently identified a human subject, whom we termed platelet defect subject 25 (PDS25) with a platelet functional disorder associated with the P2Y12 receptor. PDS25 has normal blood cell counts and no history of bleeding diathesis. However, platelets from PDS25 have virtually no response to 2-MeSADP (a stable analogue of ADP). Genetic analysis of P2Y12 from PDS25 revealed a heterozygous mutation of D121N within the DRY motif. …

Role Of Hla-I Structural Variants And The Polyreactive Antibodies They Generate In Immune Homeostasis, Mepur H Ravindranath, Fatiha El Hilali, Carly J Amato-Menker, Hajar El Hilali, Senthamil R Selvan, Edward J Filippone

Department of Medicine Faculty Papers

Cell-surface HLA-I molecules consisting of β2-microglobulin (β2m) associated heavy chains (HCs), referred to as Face-1, primarily present peptides to CD8+ T-cells. HCs consist of three α-domains, with selected amino acid sequences shared by all alleles of all six isoforms. The cell-surface HLA undergoes changes upon activation by pathological conditions with the expression of β2m-free HCs (Face-2) resulting in exposure of β2m-masked sequences shared by almost all alleles and the generation of HLA-polyreactive antibodies (Abs) against them. Face-2 may homodimerize or heterodimerize with the same (Face-3) or different alleles (Face-4) preventing exposure of shared epitopes. Non-allo immunized males naturally carry HLA-polyreactive …

Enpp1 Variants In Patients With Gaci And Pxe Expand The Clinical And Genetic Heterogeneity Of Heritable Disorders Of Ectopic Calcification., Douglas Ralph, Yvonne Nitschke, Michael A Levine, Matthew Caffet, Tamara Wurst, Amir Hossein Saeidian, Leila Youssefian, Hassan Vahidnezhad, Sharon F Terry, Frank Rutsch, Jouni Uitto, Qiaoli Li

Department of Medicine Faculty Papers

Pseudoxanthoma elasticum (PXE) and generalized arterial calcification of infancy (GACI) are clinically distinct genetic entities of ectopic calcification associated with differentially reduced circulating levels of inorganic pyrophosphate (PPi), a potent endogenous inhibitor of calcification. Variants in ENPP1, the gene mutated in GACI, have not been associated with classic PXE. Here we report the clinical, laboratory, and molecular evaluations of ten GACI and two PXE patients from five and two unrelated families registered in GACI Global and PXE International databases, respectively. All patients were found to carry biallelic variants in ENPP1. Among ten ENPP1 variants, one homozygous variant demonstrated uniparental disomy …

Medical Factors Associated With Caregiver Intention To Vaccinate Their Children Against Covid-19, Thao-Ly Phan, Paul T Enlow, Michael King, Amanda M Lewis, Anne E Kazak, Jonathan M Miller

Department of Medicine Faculty Papers

Objective: To describe medical factors that are associated with caregiver intention to vaccinate their children against COVID-19.

Methods: We conducted a cross-sectional study of families receiving primary care in a mid-Atlantic pediatric healthcare system, linking caregiver-reported data from a survey completed March 19 to April 16, 2021 to comprehensive data from the child's EHR.

Results: 513 families were included (28% Black, 16% Hispanic, 44% public insurance, 21% rural, child age range 0-21 years). 44% of caregivers intended to vaccinate their children against COVID-19, while 41% were not sure and 15% would not. After adjusting for socio-demographics, the only medical factors …

Four Faces Of Cell-Surface Hla Class-I: Their Antigenic And Immunogenic Divergence Generating Novel Targets For Vaccines, Mepur H Ravindranath, Narendranath M Ravindranath, Senthamil R Selvan, Edward J Filippone, Carly J Amato-Menker, Fatiha El Hilali

Department of Medicine Faculty Papers

Leukocyte cell-surface HLA-I molecules, involved in antigen presentation of peptides to CD8+ T-cells, consist of a heavy chain (HC) non-covalently linked to β2-microglobulin (β2m) (Face-1). The HC amino acid composition varies across all six isoforms of HLA-I, while that of β2m remains the same. Each HLA-allele differs in one or more amino acid sequences on the HC α1 and α2 helices, while several sequences among the three helices are conserved. HCs without β2m (Face-2) are also observed on human cells activated by malignancy, viral transformation, and cytokine or chemokine-mediated inflammation. In the absence of β2m, the monomeric Face-2 exposes immunogenic …

Early Morphological Changes Of The Rectus Femoris Muscle And Deep Fascia In Ullrich Congenital Muscular Dystrophy, Patrizia Sabatelli, Luciano Merlini, Alberto Di Martino, Vittoria Cenni, Cesare Faldini

Department of Medicine Faculty Papers

Ullrich congenital muscular dystrophy (UCMD) is a severe form of muscular dystrophy caused by the loss of function of collagen VI, a critical component of the muscle-tendon matrix. Magnetic resonance imaging of UCMD patients’ muscles shows a peculiar rim of abnormal signal at the periphery of each muscle, and a relative sparing of the internal part. The mechanism/s involved in the early fat substitution of muscle fiber at the periphery of muscles remain elusive. We studied a muscle biopsy of the rectus femoris/deep fascia (DF) of a 3-year-old UCMD patient, with a homozygous mutation in the COL6A2 gene. By immunohistochemical …

Synthesis, Characterization And Physicochemical Properties Of Biogenic Silver Nanoparticle-Encapsulated Chitosan Bionanocomposites, Sreelekha Ediyilyam, Mahesh M Lalitha, Bini George, Sarojini Sharath Shankar, Stanisław Wacławek, Miroslav Černík, Vinod Vellora Thekkae Padil

Department of Medicine Faculty Papers

Green bionanocomposites have garnered considerable attention and applications in the pharmaceutical and packaging industries because of their intrinsic features, such as biocompatibility and biodegradability. The work presents a novel approach towards the combined effect of glycerol, tween 80 and silver nanoparticles (AgNPs) on the physicochemical properties of lyophilized chitosan (CH) scaffolds produced via a green synthesis method.The produced bionanocomposites were characterized with the help of Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). The swelling behavior, water vapor transmission rate, moisture retention capability, degradation in Hanks solution, biodegradability in soil, mechanical strength and electrochemical performance of the composites …