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Bruce HA, Kochunov P, Paciga SA, Hyde CL, Chen X, Xie Z, Zhang B, Xi HS, O'Donnell P, Whelan C, Schubert CR, Bellon A, Ament SA, Shukla DK, Du X, Rowland LM, O'Neill H, Hong LE. Potassium channel gene associations with joint processing speed and white matter impairments in schizophrenia. Genes Brain Behav 2017; 16:515-521. [PMID: 28188958 DOI: 10.1111/gbb.12372] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 01/14/2017] [Accepted: 02/07/2017] [Indexed: 12/17/2022]
Abstract
Patients with schizophrenia show decreased processing speed on neuropsychological testing and decreased white matter integrity as measured by diffusion tensor imaging, two traits shown to be both heritable and genetically associated indicating that there may be genes that influence both traits as well as schizophrenia disease risk. The potassium channel gene family is a reasonable candidate to harbor such a gene given the prominent role potassium channels play in the central nervous system in signal transduction, particularly in myelinated axons. We genotyped members of the large potassium channel gene family focusing on putatively functional single nucleotide polymorphisms (SNPs) in a population of 363 controls, 194 patients with schizophrenia spectrum disorder (SSD) and 28 patients with affective disorders with psychotic features who completed imaging and neuropsychological testing. We then performed three association analyses using three phenotypes - processing speed, whole-brain white matter fractional anisotropy (FA) and schizophrenia spectrum diagnosis. We extracted SNPs showing an association at a nominal P value of <0.05 with all three phenotypes in the expected direction: decreased processing speed, decreased FA and increased risk of SSD. A single SNP, rs8234, in the 3' untranslated region of voltage-gated potassium channel subfamily Q member 1 (KCNQ1) was identified. Rs8234 has been shown to affect KCNQ1 expression levels, and KCNQ1 levels have been shown to affect neuronal action potentials. This exploratory analysis provides preliminary data suggesting that KCNQ1 may contribute to the shared risk for diminished processing speed, diminished white mater integrity and increased risk of schizophrenia.
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Affiliation(s)
- H A Bruce
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD
| | - P Kochunov
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD
| | - S A Paciga
- Pfizer Inc., Worldwide Research and Development, Cambridge, MA
| | - C L Hyde
- Pfizer Inc., Worldwide Research and Development, Cambridge, MA
| | - X Chen
- Pfizer Inc., Worldwide Research and Development, Cambridge, MA
| | - Z Xie
- Pfizer Inc., Worldwide Research and Development, Cambridge, MA
| | - B Zhang
- Pfizer Inc., Worldwide Research and Development, Cambridge, MA
| | - H S Xi
- Pfizer Inc., Worldwide Research and Development, Cambridge, MA
| | - P O'Donnell
- Pfizer Inc., Worldwide Research and Development, Cambridge, MA
| | - C Whelan
- Pfizer Inc., Worldwide Research and Development, Cambridge, MA
| | | | - A Bellon
- Department of Psychiatry, Penn State Hershey Medical Center, Hershey, PA, USA
| | - S A Ament
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD
| | - D K Shukla
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD
| | - X Du
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD
| | - L M Rowland
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD
| | - H O'Neill
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD
| | - L E Hong
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD
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Chiappelli J, Hong LE, Wijtenburg SA, Du X, Gaston F, Kochunov P, Rowland LM. Alterations in frontal white matter neurochemistry and microstructure in schizophrenia: implications for neuroinflammation. Transl Psychiatry 2015; 5:e548. [PMID: 25871973 PMCID: PMC4462606 DOI: 10.1038/tp.2015.43] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 01/23/2015] [Accepted: 01/27/2015] [Indexed: 01/01/2023] Open
Abstract
We investigated in vivo neurochemical markers reflective of neuronal health and glial activation to determine if these could yield clues regarding the reduced fractional anisotropy (FA) of white matter and accelerated decline of FA with age in schizophrenia. Participants with schizophrenia and healthy controls completed diffusion tensor imaging to assess FA and proton magnetic resonance spectroscopy to assess neurochemical metabolites in the same frontal region. Frontal FA was significantly lower in the schizophrenia and declined more rapidly with age compared with the healthy control group. In both groups, N-acetylaspartate (NAA), a putative marker of neuronal integrity, and glutamate declined with age, and this decline was stronger in patients. Myo-inositol, a marker of glial cells, was negatively related to FA in both groups. The relationship between FA and age remained significant in schizophrenia even when controlling for all metabolites. The relationships of FA, NAA and myo-inositol to age appear to be independent of one another. The relationship between FA and myo-inositol was independently present in both patients and controls, even after controlling for age, indicating a potential general effect of neuroinflammation on white matter microstructure. Further studies are warranted to determine the underlying mechanism driving the accelerated FA decline with age in schizophrenia.
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Affiliation(s)
- J Chiappelli
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - L E Hong
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, PO Box 21247, Baltimore, MD 21228, USA. E-mail: or
| | - S A Wijtenburg
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - X Du
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - F Gaston
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - P Kochunov
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - L M Rowland
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
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Wijtenburg SA, McGuire SA, Rowland LM, Sherman PM, Lancaster JL, Tate DF, Hardies LJ, Patel B, Glahn DC, Hong LE, Fox PT, Kochunov P. Relationship between fractional anisotropy of cerebral white matter and metabolite concentrations measured using (1)H magnetic resonance spectroscopy in healthy adults. Neuroimage 2012; 66:161-8. [PMID: 23073233 DOI: 10.1016/j.neuroimage.2012.10.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Revised: 08/31/2012] [Accepted: 10/08/2012] [Indexed: 11/27/2022] Open
Abstract
Fractional anisotropy (FA) of water diffusion in cerebral white matter (WM), derived from diffusion tensor imaging (DTI), is a sensitive index of microscopic WM integrity. Physiological and metabolic factors that explain intersubject variability in FA values were evaluated in two cohorts of healthy adults of different age spans (N=65, range: 28-50years; and N=25, age=66.6±6.2, range: 57-80years). Single voxel magnetic resonance spectroscopy (MRS) was used to measure N-acetylaspartate (NAA), total choline-containing compounds, and total creatine, bilaterally in an associative WM tract: anterior corona radiata (ACR). FA values were calculated for the underlying, proximal and two distal WM regions. Two-stage regression analysis was used to calculate the proportion of variability in FA values explained by spectroscopy measurements, at the first stage, and subject's age, at the second stage. WM NAA concentration explained 23% and 66% of intersubject variability (p<0.001) in the FA of the underlying WM in the younger and older cohorts, respectively. WM NAA concentration also explained a significant proportion of variability in FA of the genu of corpus callosum (CC), a proximal WM tract where some of the fibers contained within the spectroscopic voxel decussate. NAA concentrations also explained a significant proportion of variability in the FA values in the splenium of CC, a distal WM tract that also carries associative fibers, in both cohorts. These results suggest that MRS measurements explained a significant proportion of variability in FA values in both proximal and distal WM tracts that carry similar fiber-types.
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Affiliation(s)
- S A Wijtenburg
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - S A McGuire
- Aerospace Medicine Consultation Division, Dayton, OH, USA
| | - L M Rowland
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - P M Sherman
- Department of Neuroradiology, Wilford Hall Ambulatory Surgical Center, San Antonio, TX, USA
| | - J L Lancaster
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - D F Tate
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - L J Hardies
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - B Patel
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Physics, University of Maryland Baltimore County (UMBC), MD, USA
| | - D C Glahn
- Department of Psychiatry, Yale University and Olin Neuropsychiatric Research Center, Hartford, CT, USA
| | - L E Hong
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - P T Fox
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - P Kochunov
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Physics, University of Maryland Baltimore County (UMBC), MD, USA.
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Bustillo JR, Rowland LM, Mullins P, Jung R, Chen H, Qualls C, Hammond R, Brooks WM, Lauriello J. 1H-MRS at 4 tesla in minimally treated early schizophrenia. Mol Psychiatry 2010; 15:629-36. [PMID: 19918243 PMCID: PMC2892215 DOI: 10.1038/mp.2009.121] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We investigated glutamate-related neuronal dysfunction in the anterior cingulate (AC) early in schizophrenia before and after antipsychotic treatment. A total of 14 minimally treated schizophrenia patients and 10 healthy subjects were studied with single-voxel proton magnetic resonance spectroscopy ((1)H-MRS) of the AC, frontal white matter and thalamus at 4 T. Concentrations of N-acetylaspartate (NAA), glutamate (Glu), glutamine (Gln) and Gln/Glu ratios were determined and corrected for the partial tissue volume. Patients were treated with antipsychotic medication following a specific algorithm and (1)H-MRS was repeated after 1, 6 and 12 months. There were group x region interactions for baseline NAA (P=0.074) and Gln/Glu (P=0.028): schizophrenia subjects had lower NAA (P=0.045) and higher Gln/Glu (P=0.006) in the AC before treatment. In addition, AC Gln/Glu was inversely related to AC NAA in the schizophrenia (P=0.0009) but not in the control group (P=0.92). Following antipsychotic treatment, there were no further changes in NAA, Gln/Glu or any of the other metabolites in any of the regions studied. We conclude that early in the illness, schizophrenia patients already show abnormalities in glutamatergic metabolism and reductions in NAA consistent with glutamate-related excitotoxicity.
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Affiliation(s)
- JR Bustillo
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA,Department of Neurosciences, University of New Mexico, Albuquerque, NM, USA
| | - LM Rowland
- Maryland Psychiatric Research Center, University of Maryland, Baltimore, MD, USA
| | - P Mullins
- The Mental Illness and Neuroscience Discovery Institute, Albuquerque, NM, USA
| | - R Jung
- The Mental Illness and Neuroscience Discovery Institute, Albuquerque, NM, USA,Department of Psychology, University of New Mexico, Albuquerque, NM, USA,Department of Neurology, University of New Mexico, Albuquerque, NM, USA
| | - H Chen
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
| | - C Qualls
- Department of Mathematics & Statistics, University of New Mexico, Albuquerque, NM, USA
| | - R Hammond
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
| | - WM Brooks
- Hoglund Brain Imaging Center, Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA
| | - J Lauriello
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
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Bustillo JR, Lauriello J, Rowland LM, Jung RE, Petropoulos H, Hart BL, Blanchard J, Keith SJ, Brooks WM. Effects of chronic haloperidol and clozapine treatments on frontal and caudate neurochemistry in schizophrenia. Psychiatry Res 2001; 107:135-49. [PMID: 11566430 DOI: 10.1016/s0925-4927(01)00102-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
N-Acetyl-aspartate (NAA), a marker of neuronal integrity, has been found to be reduced in frontal regions in schizophrenia. However, the impact of antipsychotic drug type on NAA has not been carefully evaluated. We studied outpatients with schizophrenia/schizoaffective disorders chronically treated with haloperidol or clozapine and normal controls with single-voxel 1H-MRS of the caudate nuclei and the left frontal lobe. Concentrations of NAA, choline containing compounds (Cho) and creatine plus phosphocreatine (Cre) were determined and corrected for the proportion of cerebrospinal fluid (CSF) in each voxel. The haloperidol-treated group had significantly lower CSF-uncorrected and CSF-corrected left frontal NAA than the normal controls, with the clozapine group having intermediate concentrations. The haloperidol-treated group had significantly lower CSF-uncorrected caudate NAA than the normal controls, but the three groups did not differ after correcting for CSF fraction. Performance times in the Grooved Pegboard, a measure of motor dexterity and proxy for parkinsonism, were correlated with CSF-uncorrected and CSF-corrected left frontal NAA. Demographic and illness-related variables were not related to NAA. Exposure to haloperidol-like drugs may in part account for the frontal NAA reductions previously reported in schizophrenia. Adjustment for proportion of voxel CSF should be considered in 1H-MRS studies.
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Affiliation(s)
- J R Bustillo
- Department of Psychiatry, Research Division, University of New Mexico, 2400 Tucker NE, Albuquerque, NM 87131, USA.
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Forte LR, Eber SL, Fan X, London RM, Wang Y, Rowland LM, Chin DT, Freeman RH, Krause WJ. Lymphoguanylin: cloning and characterization of a unique member of the guanylin peptide family. Endocrinology 1999; 140:1800-6. [PMID: 10098518 DOI: 10.1210/endo.140.4.6630] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Guanylin and uroguanylin are small peptides containing two disulfide bonds that activate membrane guanylate cyclase-receptors in the intestine, kidney and other epithelia. Hybridization assays with a uroguanylin complementary DNA (cDNA) detected uroguanylin-like messenger RNAs (mRNAs) in the opossum spleen and testis, but these transcripts are larger than uroguanylin mRNAs. RT of RNA from spleen to produce cDNAs for amplification in the PCR followed by cloning and sequencing revealed a novel lymphoid-derived cDNA containing an open reading frame encoding a 109-amino acid polypeptide. This protein shares 84% and 40% of its residues with preprouroguanylin and preproguanylin, respectively. A 15-amino acid, uroguanylin-like peptide occurs at the COOH-terminus of the precursor polypeptide. However, this peptide is unique in having only three cysteine residues. We named the gene and its peptide product lymphoguanylin because the source of the first cDNA isolated was spleen and its mRNA is expressed in all of the lymphoid tissues tested. A 15-amino acid form of lymphoguanylin containing a single disulfide bond was synthesized that activates the guanylate cyclase receptors of human T84 intestinal and opossum kidney (OK) cells, although with less potency than uroguanylin and guanylin. Northern and/or RT-PCR assays detected lymphoguanylin mRNA transcripts in many tissues and organs of opossums, including those within the lymphoid/immune, cardiovascular/renal, reproductive, and central nervous organ systems. Lymphoguanylin joins guanylin and uroguanylin in a growing family of peptide agonists that activate transmembrane guanylate cyclase receptors, thus influencing target cell function via the intracellular second messenger, cGMP.
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Affiliation(s)
- L R Forte
- Harry S. Truman Memorial Veterans' Hospital, Department of Pharmacology, School of Medicine, Missouri University, Columbia 65212, USA.
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Abstract
An influx of Ca2+ into red blood cells of the bivalve mollusc Noetia ponderosa occurs immediately following a hypo-osmotic stress. The volume recovery response to the stress is dependent upon [Ca2+]o and is inhibited by phenothiazines. The action of these drugs is on the amino acid regulation portion of the recovery rather than on the ionic portion. Since the phenothiazines are non-specific in action, we have conducted several experiments to decide the site of phenothiazine action on the volume recovery response. The sulfoxide derivatives of both chlorpromazine and trifluoperazine have no effect on volume regulation at the same dose where the parent compound inhibits. At 50-100 times the concentration of the parent compound, the derivatives block both volume regulation and taurine efflux. The phorbol ester, TPA, an activator of protein kinase C, alters the volume recovery, but does so by affecting K+ rather than amino acid regulation. The only phenothiazine target that we can not rule out is calmodulin, which we also demonstrate to be present in the clam red cells. Thus, the data presented suggest that calmodulin is involved in the amino acid regulatory portions of the volume recovery in response to hypo-osmotic swelling.
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Affiliation(s)
- S K Pierce
- Department of Zoology, University of Maryland
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Pierce SK, Politis AD, Smith LH, Rowland LM. A Ca2+ influx in response to hypo-osmotic stress may alter osmolyte permeability by a phenothiazine-sensitive mechanism. Cell Calcium 1988; 9:129-40. [PMID: 3138029 DOI: 10.1016/0143-4160(88)90016-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The phenomenon of cell volume recovery following a hypo-osmotic stress mediated by intracellular osmolyte regulation is well known. In many, perhaps all, cell types, the osmolytes involved are usually inorganic ions and amino acids. The details of the regulatory mechanisms for the organic-type osmolytes are not well known. We have found that an immediate influx of external Ca2+ occurs coincident with the application of a hypo-osmotic stress into red cells of two invertebrate species. In both, the influx is initiated by the osmotic stress, not the concomitant ionic decrease. Volume recovery in clam red blood cells is blocked by phenothiazines. In addition, the effect of the phenothiazines is to reduce the amino acid efflux; the ionic portion of the volume response is unaffected. In contrast, the phenothiazines potentiate the volume recovery in worm red coelomocytes. A23187 also potentiates the volume recovery of the worm red cells. The results suggest that the Ca2+ influx is involved in the mechanism that alters cell membrane permeability permitting the amino acid efflux by a mechanism that may involve calmodulin.
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Affiliation(s)
- S K Pierce
- Department of Zoology, University of Maryland, Baltimore
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Peck CC, Conner DP, Bolden BJ, Almirez RG, Kingsley TE, Mell LD, Murphy MG, Hill VE, Rowland LM, Ezra D. Outward transcutaneous chemical migration: implications for diagnostics and dosimetry. Skin Pharmacol 1988; 1:14-23. [PMID: 3272746 DOI: 10.1159/000210747] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chemical substances migrate outwards from within the body to the skin surface by diffusion from cutaneous capillaries across the epidermis. Heretofore, study of transepidermal chemical emissions have been restricted to substances which are in the vapor phase at skin surface temperature. We have investigated outward transcutaneous chemical migration of nongaseous chemicals by devising an occlusive transcutaneous chemical collection system, consisting of a tape-encased plug of gelled saline in which activated carbon is dispersed. Investigations of nine chemicals in 'fuzzy' rats, rhesus monkeys, and man provide data which are consistent with a general theory of outward transcutaneous chemical migration. This noninvasive continuous transcutaneous sampling technique provides a new method for investigating skin permeability in vivo and may provide a basis for convenient diagnosis and monitoring of chemical exposure.
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Affiliation(s)
- C C Peck
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Md
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