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Gray TJ, Allmond JM, Xu Z, King TT, Lubna RS, Crawford HL, Tripathi V, Crider BP, Grzywacz R, Liddick SN, Macchiavelli AO, Miyagi T, Poves A, Andalib A, Argo E, Benetti C, Bhattacharya S, Campbell CM, Carpenter MP, Chan J, Chester A, Christie J, Clark BR, Cox I, Doetsch AA, Dopfer J, Duarte JG, Fallon P, Frotscher A, Gaballah T, Harke JT, Heideman J, Huegen H, Holt JD, Jain R, Kitamura N, Kolos K, Kondev FG, Laminack A, Longfellow B, Luitel S, Madurga M, Mahajan R, Mogannam MJ, Morse C, Neupane S, Nowicki A, Ogunbeku TH, Ong WJ, Porzio C, Prokop CJ, Rasco BC, Ronning EK, Rubino E, Ruland TJ, Rykaczewski KP, Schaedig L, Seweryniak D, Siegl K, Singh M, Stuchbery AE, Tabor SL, Tang TL, Wheeler T, Winger JA, Wood JL. Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB. Phys Rev Lett 2023; 130:242501. [PMID: 37390416 DOI: 10.1103/physrevlett.130.242501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/26/2023] [Indexed: 07/02/2023]
Abstract
Excited-state spectroscopy from the first experiment at the Facility for Rare Isotope Beams (FRIB) is reported. A 24(2)-μs isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV γ rays in coincidence with ^{32}Na nuclei. This is the only known microsecond isomer (1 μs≤T_{1/2}<1 ms) in the region. This nucleus is at the heart of the N=20 island of shape inversion and is at the crossroads of the spherical shell-model, deformed shell-model, and ab initio theories. It can be represented as the coupling of a proton hole and neutron particle to ^{32}Mg, ^{32}Mg+π^{-1}+ν^{+1}. This odd-odd coupling and isomer formation provides a sensitive measure of the underlying shape degrees of freedom of ^{32}Mg, where the onset of spherical-to-deformed shape inversion begins with a low-lying deformed 2^{+} state at 885 keV and a low-lying shape-coexisting 0_{2}^{+} state at 1058 keV. We suggest two possible explanations for the 625-keV isomer in ^{32}Na: a 6^{-} spherical shape isomer that decays by E2 or a 0^{+} deformed spin isomer that decays by M2. The present results and calculations are most consistent with the latter, indicating that the low-lying states are dominated by deformation.
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Affiliation(s)
- T J Gray
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J M Allmond
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Z Xu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - T T King
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R S Lubna
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - V Tripathi
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - B P Crider
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - R Grzywacz
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - S N Liddick
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - A O Macchiavelli
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T Miyagi
- Department of Physics, Technische Universität Darmstadt, Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - A Poves
- Departamento de Fìsica Teórica and IFT-UAM/CSIC, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - A Andalib
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Argo
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Benetti
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - S Bhattacharya
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - C M Campbell
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Chan
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Chester
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Christie
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - B R Clark
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - I Cox
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A A Doetsch
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Dopfer
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J G Duarte
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Fallon
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A Frotscher
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - T Gaballah
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - J T Harke
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Heideman
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - H Huegen
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - J D Holt
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, McGill University, Montréal, Quebec City H3A 2T8, Canada
| | - R Jain
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - N Kitamura
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - K Kolos
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Laminack
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B Longfellow
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S Luitel
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - M Madurga
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - R Mahajan
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - M J Mogannam
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Morse
- National Nuclear Data Center, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - S Neupane
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Nowicki
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - T H Ogunbeku
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - W-J Ong
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Porzio
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C J Prokop
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B C Rasco
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E K Ronning
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Rubino
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - T J Ruland
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - K P Rykaczewski
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L Schaedig
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - K Siegl
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - M Singh
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A E Stuchbery
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - S L Tabor
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T L Tang
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T Wheeler
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J A Winger
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - J L Wood
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA
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Crawford HL, Tripathi V, Allmond JM, Crider BP, Grzywacz R, Liddick SN, Andalib A, Argo E, Benetti C, Bhattacharya S, Campbell CM, Carpenter MP, Chan J, Chester A, Christie J, Clark BR, Cox I, Doetsch AA, Dopfer J, Duarte JG, Fallon P, Frotscher A, Gaballah T, Gray TJ, Harke JT, Heideman J, Heugen H, Jain R, King TT, Kitamura N, Kolos K, Kondev FG, Laminack A, Longfellow B, Lubna RS, Luitel S, Madurga M, Mahajan R, Mogannam MJ, Morse C, Neupane S, Nowicki A, Ogunbeku TH, Ong WJ, Porzio C, Prokop CJ, Rasco BC, Ronning EK, Rubino E, Ruland TJ, Rykaczewski KP, Schaedig L, Seweryniak D, Siegl K, Singh M, Tabor SL, Tang TL, Wheeler T, Winger JA, Xu Z. Crossing N=28 Toward the Neutron Drip Line: First Measurement of Half-Lives at FRIB. Phys Rev Lett 2022; 129:212501. [PMID: 36461950 DOI: 10.1103/physrevlett.129.212501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/14/2022] [Indexed: 06/17/2023]
Abstract
New half-lives for exotic isotopes approaching the neutron drip-line in the vicinity of N∼28 for Z=12-15 were measured at the Facility for Rare Isotope Beams (FRIB) with the FRIB decay station initiator. The first experimental results are compared to the latest quasiparticle random phase approximation and shell-model calculations. Overall, the measured half-lives are consistent with the available theoretical descriptions and suggest a well-developed region of deformation below ^{48}Ca in the N=28 isotones. The erosion of the Z=14 subshell closure in Si is experimentally confirmed at N=28, and a reduction in the ^{38}Mg half-life is observed as compared with its isotopic neighbors, which does not seem to be predicted well based on the decay energy and deformation trends. This highlights the need for both additional data in this very exotic region, and for more advanced theoretical efforts.
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Affiliation(s)
- H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - V Tripathi
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - J M Allmond
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B P Crider
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - R Grzywacz
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - S N Liddick
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Andalib
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Argo
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Benetti
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - S Bhattacharya
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - C M Campbell
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Chan
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Chester
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Christie
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - B R Clark
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - I Cox
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A A Doetsch
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Dopfer
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J G Duarte
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Fallon
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A Frotscher
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - T Gaballah
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - T J Gray
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J T Harke
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Heideman
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - H Heugen
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - R Jain
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - T T King
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - N Kitamura
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - K Kolos
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Laminack
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B Longfellow
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R S Lubna
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Luitel
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - M Madurga
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - R Mahajan
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - M J Mogannam
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Morse
- Brookhaven National Laboratory, Upton, New York 11973, USA
| | - S Neupane
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Nowicki
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - T H Ogunbeku
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - W-J Ong
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Porzio
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C J Prokop
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B C Rasco
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E K Ronning
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Rubino
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - T J Ruland
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - K P Rykaczewski
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L Schaedig
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - K Siegl
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - M Singh
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - S L Tabor
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T L Tang
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T Wheeler
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J A Winger
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - Z Xu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
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Kwon Y, Wiles C, Parker BE, Clark BR, Sohn MW, Mariani S, Hahn JO, Jacobs DR, Stein JH, Lima J, Kapur V, Wellman A, Redline S, Azarbarzin A. Pulse arrival time, a novel sleep cardiovascular marker: the multi-ethnic study of atherosclerosis. Thorax 2021; 76:1124-1130. [PMID: 33863828 DOI: 10.1136/thoraxjnl-2020-216399] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 10/21/2020] [Revised: 01/29/2021] [Accepted: 03/14/2021] [Indexed: 11/03/2022]
Abstract
BACKGROUND Pulse arrival time (PAT) is commonly used to estimate blood pressure response. We hypothesised that PAT response to obstructive respiratory events would be associated with increased cardiovascular risk in people with obstructive sleep apnoea. METHODS PAT, defined as the time interval between electrocardiography R wave and pulse arrival by photoplethysmography, was measured in the Multi-Ethnic Study of Atherosclerosis Sleep study participants. The PAT response to apnoeas/hypopnoeas was defined as the area under the PAT waveform following respiratory events. Cardiovascular outcomes included markers of subclinical cardiovascular disease (CVD): left ventricular mass, carotid plaque burden score and coronary artery calcification (CAC) (cross-sectional) and incident composite CVD events (prospective). Multivariable logistic and Cox proportional hazard regressions were performed. RESULTS A total of 1407 participants (mean age 68.4 years, female 47.5%) were included. Higher PAT response (per 1 SD increase) was associated with higher left ventricular mass (5.7 g/m2 higher in fourth vs first quartile, p<0.007), higher carotid plaque burden score (0.37 higher in fourth vs first quartile, p=0.02) and trended to greater odds of CAC (1.44, 95% CI 0.98 to 2.15, p=0.06). A total of 65 incident CVD events were observed over the mean of 4.1 (2.6) years follow-up period. Higher PAT response was associated with increased future CVD events (HR: 1.20, 95% CI 1.02 to 1.42, p=0.03). CONCLUSION PAT is independently associated with markers of subclinical CVD and incident CVD events. Respiratory-related PAT response is a novel and promising polysomnography metric with cardiovascular implications.
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Affiliation(s)
- Younghoon Kwon
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | | | | | - Brian R Clark
- Barron Associates, Inc, Charlottesville, Virginia, USA
| | - Min-Woong Sohn
- Department of Health Management & Policy, College of Public Health, University of Kentucky, Lexington, Kentucky, USA
| | - Sara Mariani
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Jin-Oh Hahn
- Department of Mechanical Engineering, University of Maryland at College Park, College Park, Maryland, USA
| | - David R Jacobs
- Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - James H Stein
- University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Joao Lima
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Vishesh Kapur
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Andrew Wellman
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Susan Redline
- Department of Medicine, Brigham and Women's Hospital and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Ali Azarbarzin
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
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Kong CJ, Gilliland SE, Clark BR, Gupton BF. Highly-active, graphene-supported platinum catalyst for the solventless hydrosilylation of olefins. Chem Commun (Camb) 2018; 54:13343-13346. [PMID: 30411738 DOI: 10.1039/c8cc07641c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein we report the development of the first graphene-supported platinum catalyst that has demonstrated exceptional catalytic activity and stability for hydrosilylation reactions of olefins (TOF 4.8 × 106 h-1, TON = 9.4 × 106). The catalyst also exhibited functional group tolerance over a broad range of industrially relevant substrates with minimal metal leaching. In addition, the catalyst system was successfully translated into a packed bed platform for continuous hydrosilylation reactions.
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Affiliation(s)
- Caleb J Kong
- Department of Chemistry and Department of Chemical and Life Science Engineering, Virginia Commonwealth University, 601 W. Main St. Richmond, VA 23220, USA.
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Cook AJ, Roberts DA, Nelson KC, Clark BR, Parker BE. Development of a pictorial scale for assessing functional interference with chronic pain: the Pictorial Pain Interference Questionnaire. J Pain Res 2018; 11:1343-1354. [PMID: 30050318 PMCID: PMC6055905 DOI: 10.2147/jpr.s160801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Assessment of function and functional interference is an important component of chronic pain assessment and treatment and is commonly based on self-report questionnaires. Existing questionnaires for assessing functional interference are language dependent, which can limit their utility for patients across cultures with literacy, fluency, or cognitive restrictions. Objective The objectives of this study were to create a tool with minimal language dependence and literacy requirement for measuring functional interference due to chronic pain and evaluate the psychometric properties and usability of this new assessment scale, the Pictorial Pain Interference Questionnaire (PPIQ), in a clinical sample of participants with chronic pain. Design The study employed a prospective, cross-sectional design in a clinical chronic pain setting. Participants and methods A total of 113 participants with chronic non-cancer pain were recruited from a private chronic pain clinic. A pictorial scale was developed and tested via psychometric procedures, including comparisons with validated measures of functional interference and related chronic pain constructs. Results Excellent internal consistency reliability (a=0.91), good construct validity (total score: r=0.72–0.81), and adequate-to-good convergent and discriminant validities were demonstrated through comparative analyses with existing self-report questionnaires. A scoring metric for classifying low, moderate, and high levels of interference was found to have good construct validity. Evaluation of satisfaction revealed adequate understanding of the PPIQ among most users. Conclusion Initial support for the PPIQ as an alternative to language-based questionnaires for assessing functional interference from chronic pain was found. Subsequent research will help to clarify psychometric properties of the PPIQ and user response among various chronic pain subgroups.
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Affiliation(s)
- Andrew J Cook
- Department of Psychiatry and Behavioral Science, Texas A&M Health Science Center College of Medicine, Temple, TX, USA,
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Alley WM, Clark BR, Ely DM, Faunt CC. Groundwater Development Stress: Global-Scale Indices Compared to Regional Modeling. Ground Water 2018; 56:266-275. [PMID: 28810076 DOI: 10.1111/gwat.12578] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/06/2017] [Accepted: 07/12/2017] [Indexed: 06/07/2023]
Abstract
The increased availability of global datasets and technologies such as global hydrologic models and the Gravity Recovery and Climate Experiment (GRACE) satellites have resulted in a growing number of global-scale assessments of water availability using simple indices of water stress. Developed initially for surface water, such indices are increasingly used to evaluate global groundwater resources. We compare indices of groundwater development stress for three major agricultural areas of the United States to information available from regional water budgets developed from detailed groundwater modeling. These comparisons illustrate the potential value of regional-scale analyses to supplement global hydrological models and GRACE analyses of groundwater depletion. Regional-scale analyses allow assessments of water stress that better account for scale effects, the dynamics of groundwater flow systems, the complexities of irrigated agricultural systems, and the laws, regulations, engineering, and socioeconomic factors that govern groundwater use. Strategic use of regional-scale models with global-scale analyses would greatly enhance knowledge of the global groundwater depletion problem.
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Affiliation(s)
- William M Alley
- National Ground Water Association, 601 Dempsey Road, Westerville, OH, 43081
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Shah KM, Clark BR, McGill JB, Mueller MJ. Upper extremity impairments, pain and disability in patients with diabetes mellitus. Physiotherapy 2014; 101:147-54. [PMID: 25442298 DOI: 10.1016/j.physio.2014.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [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: 11/04/2013] [Accepted: 07/25/2014] [Indexed: 12/25/2022]
Abstract
OBJECTIVES To determine the severity of, and relationships between, upper extremity impairments, pain and disability in patients with diabetes mellitus, and to compare upper extremity impairments in patients with diabetes with non-diabetic controls. DESIGN Case-control, cross-sectional design. SETTING University-based, outpatient diabetes centre and physical therapy research clinic. PARTICIPANTS Two hundred and thirty-six patients with diabetes attending an outpatient diabetes clinic completed the Shoulder Pain and Disability Index (SPADI) questionnaire. A detailed shoulder and hand examination was conducted on a subgroup of 29 volunteers with type 2 diabetes, and 27 controls matched for age, sex and body mass index. INTERVENTIONS None. MAIN OUTCOME MEASURES SPADI score, passive shoulder range of motion (ROM) and strength, grip strength, hand sensation, dexterity and limited joint mobility of the hand. RESULTS Sixty-three percent (149/236) of patients with diabetes reported shoulder pain and/or disability [median SPADI score 10.0 (interquartile range 0.0 to 39.6)]. Compared with the control group, the subgroup of patients with diabetes had substantial reductions in shoulder ROM, shoulder muscle strength, grip and key pinch strength (P<0.05). Patients with diabetes had a greater prevalence of decreased sensation (26/27 vs 14/27) and limited joint mobility of the hand (17/27 vs 4/27) compared with the control group. Total SPADI score was negatively correlated (P<0.05) with shoulder ROM (r=-0.42 to -0.74) and strength measures (r=-0.44 to -0.63) in patients with diabetes. CONCLUSIONS Upper extremity impairments in this sample of patients with diabetes were common, severe and related to complaints of pain and disability. Additional research is needed to understand the unique reasons for upper extremity problems in patients with diabetes, and to identify preventative treatments.
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Affiliation(s)
- K M Shah
- Program in Physical Therapy, Washington University School of Medicine in St. Louis, USA.
| | - B R Clark
- Program in Physical Therapy, Washington University School of Medicine in St. Louis, USA
| | - J B McGill
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine in St. Louis, USA
| | - M J Mueller
- Program in Physical Therapy, Washington University School of Medicine in St. Louis, USA; Department of Radiology, Washington University School of Medicine in St. Louis, USA
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Clark BR, Wiles CJ, Lee JM, Bhammar DM, Sawyer BJ, Parker BE, Gaesser GA, Welk GJ. Validation Of A Wireless, Multimode, Polynomial Neural Network-based Physical Activity Monitor In Children. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000494993.40720.23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lovat LB, Johnson K, Mackenzie GD, Clark BR, Novelli MR, Davies S, O'Donovan M, Selvasekar C, Thorpe SM, Pickard D, Fitzgerald R, Fearn T, Bigio I, Bown SG. Elastic scattering spectroscopy accurately detects high grade dysplasia and cancer in Barrett's oesophagus. Gut 2006; 55:1078-83. [PMID: 16469795 PMCID: PMC1856278 DOI: 10.1136/gut.2005.081497] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND AIMS Endoscopic surveillance of Barrett's oesophagus currently relies on multiple random biopsies. This approach is time consuming, has a poor diagnostic yield, and significant interobserver variability. Elastic scattering spectroscopy is a real time in vivo optical technique which detects changes in the physical properties of cells. The aim of this study was to assess the potential for elastic scattering to detect high grade dysplasia or cancer within Barrett's oesophagus. METHODS Elastic scattering spectroscopy measurements collected in vivo were matched with histological specimens taken from identical sites within Barrett's oesophagus. All biopsies were reviewed by three gastrointestinal pathologists and defined as either "low risk" (non-dysplastic or low grade dysplasia) or "high risk" (high grade dysplasia or cancer). Two different statistical approaches (leave one out and block validation) were used to validate the model. RESULTS A total of 181 matched biopsy sites from 81 patients, where histopathological consensus was reached, were analysed. There was good pathologist agreement in differentiating high grade dysplasia and cancer from other pathology (kappa = 0.72). Elastic scattering spectroscopy detected high risk sites with 92% sensitivity and 60% specificity and differentiated high risk sites from inflammation with a sensitivity and specificity of 79%. If used to target biopsies during endoscopy, the number of low risk biopsies taken would decrease by 60% with minimal loss of accuracy. A negative spectroscopy result would exclude high grade dysplasia or cancer with an accuracy of >99.5%. CONCLUSIONS These preliminary results show that elastic scattering spectroscopy has the potential to target conventional biopsies in Barrett's surveillance saving significant endoscopist and pathologist time with consequent financial savings. This technique now requires validation in prospective studies.
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Affiliation(s)
- L B Lovat
- National Medical Laser Centre, Department of Surgery, Royal Free and University College Medical School, University College London, UK.
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Clark BR. Preparation of nicotinic-5-2H acid from 5-bromonicotinic acid. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580120408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Gaesser GA, Clark BR, Parker BE, Olowin AB, Richardson NT, Blessinger JR, Sawyer BJ, Davis CK, Welk GJ, Irving BA. Validation Of An Integrated Heart Rate/Physical Activity Monitor. Med Sci Sports Exerc 2006. [DOI: 10.1249/00005768-200605001-03189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bubnic SJ, Wang XH, Clark BR, Keating A. W/Wv marrow stromal cells engraft and enhance early erythropoietic progenitors in unconditioned Sl/Sld murine recipients. Bone Marrow Transplant 2002; 30:867-72. [PMID: 12476278 DOI: 10.1038/sj.bmt.1703761] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2002] [Accepted: 09/13/2002] [Indexed: 11/09/2022]
Abstract
Transplantation of marrow stromal cells may provide a means of modulating hematopoiesis and serve as a form of cell therapy. We employed a murine transplant model using Sl/Sl(d) mice, which have macrocytic anemia due to defective expression of stem cell factor (SCF) on bone marrow stromal cells. Donor cells were derived from the complementary mutant strain W/W(v), which also exhibit anemia, due to mutations in c-kit, the SCF receptor expressed on hematopoietic stem cells. The strength of this model is that any correction of the Sl/Sl(d) anemia from the infusion of W/W(v) stromal cells can be attributed to the effect of the stromal cells and not to contaminating W/W(v) hematopoietic stem cells, a major concern in experiments involving wild-type animals. Cultured stromal cells were infused into unconditioned non-splenectomized Sl/Sl(d) mice. Engraftment of donor stromal cells reached levels of up to 1.0% of total marrow cells 4 months post transplant. However, stromal engraftment was not detectable in the spleen. Recipients of W/W(v) stroma showed a significant increase in the committed erythroid progenitors compared with those receiving Sl/Sl(d) stromal cells: 109 +/- 26 vs 68 +/- 5 CFU-E per 10(5) BMC, P = 0.002; 25 +/- 10 vs 15 +/- 5 BFU-E per 10(5) BMC, P = 0.037, for W/W(v) and Sl/Sl(d) stroma recipients, respectively. Despite this increase in erythroid progenitors, the anemia was not corrected. Our data suggest that in this murine model, splenic erythropoiesis may influence stromal cell therapy, and that higher levels of marrow engraftment may be necessary to obtain a clinically significant effect.
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Affiliation(s)
- S J Bubnic
- Toronto General Research Institute, Toronto, ON, Canada
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Tolbert DL, Bradley MW, Tolod EG, Torres-Aleman I, Clark BR. Chronic intraventricular infusion of glial cell line-derived neurotrophic factor (GDNF) rescues some cerebellar Purkinje cells from heredodegeneration. Exp Neurol 2001; 170:375-9. [PMID: 11476604 DOI: 10.1006/exnr.2001.7718] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cerebellar Purkinje cells degenerate in shaker mutant rats. Glia cell line-derived neurotrophic factor (GDNF) was chronically infused intraventricularly in an attempt to rescue mutant Purkinje cells from dying. Four weeks of chronic GDNF infusion delayed the degeneration of many but not all Purkinje cells. Surviving Purkinje cells formed spatially related groups interrupted by other groups of degenerated Purkinje cells. There was a positive correlation in GDNF-supported Purkinje cell survival and persistence of normal motor behaviors.
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Affiliation(s)
- D L Tolbert
- Francis and Doris Murphy Neuroanatomy Research Laboratory, Department of Anatomy and Neurobiology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
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Abstract
Brainstem inferior olivary neurons, through their olivocerebellar efferent projections, dynamically regulate the structure and function of Purkinje neurons. To test the hypothesis that the inferior olive can epigenetically modify adult-onset hereditary Purkinje cell death, olivocerebellar projections were destroyed by 3-acetylpyridine chemoablation of the inferior olive in Shaker mutant rats. Starting around seven weeks of age, mutant Purkinje cells degenerate in a highly predictable spatial and temporal pattern. Chemoablation of the inferior olive at the onset of hereditary Purkinje cell degeneration accelerated the temporal pattern of Purkinje cell death from a natural phenotypic course of six to eight weeks to one and two weeks. When chemoablation of the inferior olive was performed three and a half weeks earlier, the onset of Purkinje cell death was accelerated by seven to 10days, but the spatial pattern and natural rate of temporal degeneration was maintained. Chemoablation of the inferior olive in normal rats did not result in any apparent death of Purkinje cells. These findings indicate that the olivocerebellar system can markedly modify hereditary Purkinje cell death. The accelerated death of Purkinje cells following chemoablation of the inferior olive can result from either the interruption of a trophic signal by climbing fiber deafferentation or parallel fiber excitotoxicity due to cortical disinhibition, but not due to olivocerebellar excitotoxicity.
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Affiliation(s)
- D L Tolbert
- Francis and Doris Murphy Neuroanatomy Research Laboratory, Department of Anatomy and Neurobiology, and Department of Surgery (Neurosurgery), Saint Louis University School of Medicine, St Louis, MO 63104, USA.
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Abstract
This study reports on the mode of inheritance of the shaker mutation and the development of an inbred strain of the shaker rat mutation from Sprague Dawley outbred stock onto a Wistar Furth background. Neuroanatomical and behavioral expression of the affected phenotype, through seven generations of backcross and intercross breeding, has confirmed the mode of inheritance to be X-linked. Behaviorally, affected mutants present with a wide-based ataxic gait and whole body tremor. In affected mutants calbindin immunostaining for surviving cerebellar Purkinje cells revealed widespread degeneration in the anterior lobe and in limited areas of the posterior lobe. Fast Fourier transform analysis of the tremor revealed a frequency of 3-5 Hz. As predicted by X-linked inheritance, female descendants of an affected male are carriers for the genotype and the phenotype is expressed in one-half of her male offspring. There was spatially random and limited degeneration of Purkinje cells in carrier females, but they did not display overt clinical signs of ataxia and tremor. These data provide further support for using the shaker mutant rat as an animal model for studies of mechanisms underlying human heredodegenerative diseases.
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Affiliation(s)
- B R Clark
- Program in Physical Therapy, Washington University School of Medicine, Campus Box 8502, 4444 Forest Park Blvd., St. Louis, MO 63108, USA.
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Povinelli DJ, Landry AM, Theall LA, Clark BR, Castille CM. Development of young children's understanding that the recent past is causally bound to the present. Dev Psychol 1999. [PMID: 10563732 DOI: 10.1037//0012-1649.35.6.1426] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The results of 6 studies (involving 304 children) suggested that 4- and 5-year-olds, but not 3-year-olds, understand that very recent past events determine the present. In Studies 1-3, 3- and 4-year-old children were introduced to 2 empty hiding locations. With children's backs to these locations, a camera recorded an experimenter secretly hiding a puppet in one of them. Children then viewed the videotape of what had just happened, along with another tape that depicted identical events except with a different child and with the puppet hidden in the other location. Only 4-year-olds were subsequently able to locate the puppet, even though 3-year-olds remembered the contents of the tapes and understood the equivalence between the video events and the real world. In Study 4, similar effects were obtained when a verbal analog of the test was presented to 3-5-year-olds. Studies 5 and 6 showed that when children observed 2 events in which they had just participated, only 5-year-olds understood that the most recent events were relevant.
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Affiliation(s)
- D J Povinelli
- Center for Child Studies, University of Southwestern Louisiana 70504-4287, USA
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Povinelli DJ, Landry AM, Theall LA, Clark BR, Castille CM. Development of young children's understanding that the recent past is causally bound to the present. Dev Psychol 1999; 35:1426-39. [PMID: 10563732 DOI: 10.1037/0012-1649.35.6.1426] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The results of 6 studies (involving 304 children) suggested that 4- and 5-year-olds, but not 3-year-olds, understand that very recent past events determine the present. In Studies 1-3, 3- and 4-year-old children were introduced to 2 empty hiding locations. With children's backs to these locations, a camera recorded an experimenter secretly hiding a puppet in one of them. Children then viewed the videotape of what had just happened, along with another tape that depicted identical events except with a different child and with the puppet hidden in the other location. Only 4-year-olds were subsequently able to locate the puppet, even though 3-year-olds remembered the contents of the tapes and understood the equivalence between the video events and the real world. In Study 4, similar effects were obtained when a verbal analog of the test was presented to 3-5-year-olds. Studies 5 and 6 showed that when children observed 2 events in which they had just participated, only 5-year-olds understood that the most recent events were relevant.
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Affiliation(s)
- D J Povinelli
- Center for Child Studies, University of Southwestern Louisiana 70504-4287, USA
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Lutzko C, Kruth S, Abrams-Ogg AC, Lau K, Li L, Clark BR, Ruedy C, Nanji S, Foster R, Kohn D, Shull R, Dubé ID. Genetically corrected autologous stem cells engraft, but host immune responses limit their utility in canine alpha-L-iduronidase deficiency. Blood 1999; 93:1895-905. [PMID: 10068662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Canine alpha-L-iduronidase (alpha-ID) deficiency, a model of the human storage disorder mucopolysaccharidosis type I (MPS I), is an ideal system in which to evaluate the clinical benefit of genetically corrected hematopoietic stem cells. We performed adoptive transfer of genetically corrected autologous hematopoietic cells in dogs with alpha-ID deficiency. Large volume marrow collections were performed on five alpha-ID-deficient dogs. Marrow mononuclear cells in long-term marrow cultures (LTMCs) were exposed on three occasions during 3 weeks of culture to retroviral vectors bearing the normal canine alpha-ID cDNA. Transduced LTMC cells from deficient dogs expressed enzymatically active alpha-ID at 10 to 200 times the levels seen in normal dogs. An average of 32% of LTMC-derived clonogenic hematopoietic cells were provirus positive by polymerase chain reaction and about half of these expressed alpha-ID. Approximately 10(7) autologous gene-modified LTMC cells/kg were infused into nonmyeloablated recipients. Proviral DNA was detected in up to 10% of individual marrow-derived hematopoietic colonies and in 0.01% to 1% of blood and marrow leukocytes at up to 2 to 3 years postinfusion. Despite good evidence for engraftment of provirally marked cells, neither alpha-ID enzyme nor alpha-ID transcripts were detected in any dog. We evaluated immune responses against alpha-ID and transduced cells. Humoral responses to alpha-ID and serum components of the culture media (fetal bovine and horse sera and bovine serum albumin) were identified by enzyme-linked immunosorbent assay. Cellular immune responses to autologous alpha-ID but not neo(r) transduced cells were demonstrated by lymphocyte proliferation assays. To abrogate potential immune phenomena, four affected dogs received posttransplant cyclosporine A. Whereas immune responses were dampened in these dogs, alpha-ID activity remained undetectable. In none of the dogs engrafted with genetically corrected cells was there evidence for clinical improvement. Our data suggest that, whereas the alpha-ID cDNA may be transferred and maintained in approximately 5% of hematopoietic progenitors, the potential of this approach appears limited by the levels of provirally derived enzyme that are expressed in vivo and by the host's response to cultured and transduced hematopoietic cells expressing foreign proteins.
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Affiliation(s)
- C Lutzko
- Department of Laboratory Medicine, Sunnybrook Health Science Centre, and the Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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Clark BR, Everall IP. What is the role of the HIV liaison psychiatrist? Genitourin Med 1997; 73:568-70. [PMID: 9582488 PMCID: PMC1195952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In this article we review the field of HIV liaison psychiatry and illustrate the manner in which psychiatric care can contribute to the health and quality of life of this group of patients. To illustrate our discussion we review experience and findings in relation to affective illness, cognitive impairments, and personality disorder in HIV infection. We also highlight some of the areas where psychiatric care of people with HIV infection is unique from other types of psychiatric liaison work.
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Affiliation(s)
- B R Clark
- Maudsley Hospital, Denmark Hill, London
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23
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Clark BR, Jamieson C, Keating A. In vitro clonal culture of human hematopoietic progenitor cells. Methods Mol Biol 1997; 75:257-63. [PMID: 9276275 DOI: 10.1385/0-89603-441-0:257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- B R Clark
- University of Toronto Autologous Blood and Marrow Transplant Program, Toronto Hospital, Ontario, Canada
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Affiliation(s)
- B R Clark
- University of Toronto Autologous Blood and Marrow Transplant Program, Toronto Hospital, Ontario, Canada
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25
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Sandhu JS, Clark BR, Boynton EL, Atkins H, Messner H, Keating A, Hozumi N. Human hematopoiesis in SCID mice implanted with human adult cancellous bone. Blood 1996; 88:1973-82. [PMID: 8822916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The persistence of hematopoietic cells from human adult cancellous bone fragments implanted subcutaneously into CB-17 scid/scid mice was studied. Recipient mice received either no pretreatment (control group) or pretreatment with 3 Gy total-body irradiation and anti-asialo GM1 sera (ASGM1; pretreated group) before implantation. Pretreated severe combined immunodeficient (SCID) mice implanted with human bone were subsequently given ASGM1 every 7 days for the duration of the experiments. At 12 weeks postimplantation, flow cytometry of cells from pretreated and control animal tissues detected human CD45+ cells in the mouse spleen (mean, 7.8% and 3.4% positive cells, pretreated and control animals, respectively), bone marrow (BM; mean, 16.5% and 4.8% positive cells, respectively), and blood (mean, 5.5% and < 2% positive cells, respectively), and in the implanted human bone (73% and 8.9% positive cells, respectively). At 12 weeks, pretreated mice had human granulocyte-macrophage colony-forming cells (GM-CFC) and burst-forming units-erythrocyte (BFU-E) in the implanted human bone in the murine BM and in some of the spleens. The spleens also had extensive infiltration of human B cells and macrophages. Mean serum levels of human IgG in pretreated animals were 14 micrograms/mL during weeks 6 to 12, compared with trace levels (< 1 microgram/mL) in control mice. Bone from patients with acute myeloblastic leukemia (AML) was also implanted in pretreated SCID mice, and retrieved at 8 weeks for analysis. Comparison of preimplantation and implanted samples showed that the original histology was maintained, and massive infiltration of human CD68+ cells was observed in the mice spleens and BM. Implantation of AML bone in SCID mice facilitates analysis of in situ AML cell interaction with stromal cells in the leukemic state, and therapies against AML can be tested in this system, especially the selective killing of AML cells in the presence of other BM cells. Furthermore, this model requires no exogenous administration of cytokines to maintain human hematopoiesis with both normal or AML bone. Because the structure and function of both normal and diseased human adult bone is maintained, this animal model should facilitate investigation of both normal human hematopoiesis and hematopoietic malignancies.
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Affiliation(s)
- J S Sandhu
- Department of Surgery, University of Toronto, Ontario, Canada
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Abstract
The marrow microenvironment is a complex, three-dimensional structure composed of many cell types and abundant extracellular matrix. Much of the data are derived from analysis of the adherent layer of murine and, especially, human long-term marrow cultures. An essential feature of this in vitro counterpart to the marrow microenvironment is the presence of flat angulated cells functionally defined as marrow stromal cells with the following phenotype: type IV collagen(+), laminin(+), vimentin(+), CD10(+), muscle actin(+), Stro-1(+), and negative for CD45, Mac-1, and HLA-DR. Stromal precursors are Stro-1(+) and CD34(+). Regulation of hematopoietic precursors by the microenvironment occurs by elaboration of regulatory molecules such as hematopoietic cytokines, by cell-cell contact via adhesion molecules such as alpha 4 beta 1 integrin, and by interactions with components of the extracellular matrix as in the case of the glycosaminoglycan hyaluronic acid with cell-associated CD44. Although little about the regulation of stromal cell development itself is known, several studies indicate the transplantability of marrow stromal cells under specific conditions. These developments suggest a potential role of stromal cells in cell therapy. Transfected stromal cells may serve as suitable vehicles for gene delivery to correct single gene disorders in which the product of the target gene does not require stringent regulation as, for example, in the correction of Factor VIII and Factor IX deficiency. Further studies are warranted to investigate marrow stromal cell physiology and regulation to better understand hematopoiesis and to explore the possible use of stroma in therapy.
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Affiliation(s)
- B R Clark
- University of Toronto Autologous Blood and Marrow Transplant, Toronto Hospital, Ontario, Canada
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Zimmerman DR, Karon SL, Arling G, Clark BR, Collins T, Ross R, Sainfort F. Development and testing of nursing home quality indicators. Health Care Financ Rev 1995; 16:107-27. [PMID: 10151883 PMCID: PMC4193525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this article, the authors report on the development and testing of a set of indicators of quality of care in nursing homes, using resident-level assessment data. These quality indicators (QIs) have been developed to provide a foundation for both external and internal quality-assurance (QA) and quality-improvement activities. The authors describe the development of the QIs, discuss their nature and characteristics, address the development of a QI-based quality-monitoring system (QMS), report on a pilot test of the QIs and the system, comment on methodological and current QI validation efforts, and conclude by raising further research and development issues.
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Affiliation(s)
- D R Zimmerman
- Center for Health Systems Research and Analysis, University of Madison-Wisconsin, USA
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Abstract
Antigen-specific T-cell activation requires the formation of a transient cell-cell conjugate between a T cell and an appropriate antigen presenting cell (APC). Focal aggregation of T-cell receptor (TCR) molecules at the T-cell-APC membrane interface accompanies formation of multiple non-covalent intercellular bridges consisting of TCRs on the T cell and cognate MHC-peptide complexes on the APC. Enhanced adhesiveness and T-cell activation follow the T-cell signalling that results from crosslinking of T-cell receptors (TCR). Models of T-cell activation propose that the APC and activated T cell separate following a decline in the enhanced adhesiveness. The rate of intercellular TCR-(MHC-peptide) complexes formed during T-cell activation is unknown. Based on the reported CD4-positive T-cell internalization of the peptide moiety of preformed cognate MHC II-peptide complexes, it is proposed here that translocation of the peptide moiety leads to destabilization and decomposition of intercellular trimolecular TCR-(MHC-peptide) complexes in the T-cell-APC interface. This decomposition accompanies or results in the decline in enhanced adhesiveness leading to separation of the APC and activated T cell.
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Affiliation(s)
- B R Clark
- Ekagen Corporation, Redwood City, CA 94061, USA
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Tolbert DL, Pittman T, Alisky JM, Clark BR. Chronic NMDA receptor blockade or muscimol inhibition of cerebellar cortical neuronal activity alters the development of spinocerebellar afferent topography. Brain Res Dev Brain Res 1994; 80:268-74. [PMID: 7525115 DOI: 10.1016/0165-3806(94)90112-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The requirement for cerebellar cortical neuronal activity in the development of spinocerebellar afferent topography was investigated in neonatal rats. In adult rats lower thoracic-upper lumbar spinocerebellar projections are localized to sharply circumscribed patches in the granule cell layer of the cerebellar anterior lobe. In transverse sections these patches appear as sagittally oriented stripes. This pattern develops postnatally as many spinal axons which initially project between the incipient stripes are eliminated thereby sharpening the stripe boundaries. We attempted to alter cerebellar cortical neuronal activity in neonatal animals to study the effects of these changes on the development of spinocerebellar stripes. In some experiments glutaminergic excitatory synaptic transmission was chronically blocked with the N-methyl-D-aspartate (NMDA) receptor antagonist 2-aminophosphovaleric acid (APV). In other experiments postsynaptic activity was directly inhibited by the gamma-aminobutyric acid agonist muscimol. Chronic exposure to APV or to muscimol did not affect the initial development of spinocerebellar projections; many spinal axons were present in the anterior lobe and arranged in incipient stripes. Both the APV and the muscimol appeared to prevent the elimination of interstripe projections; consequently the boundaries of the stripes remained poorly defined. These findings suggest that cerebellar cortical neuronal activity is a necessary requirement for the refinement of spinal afferent topography in the anterior lobe.
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Affiliation(s)
- D L Tolbert
- Francis and Doris Murphy Neuroanatomy Research Laboratory, Department of Anatomy and Neurobiology, MO 63104-1028
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Clark BR, Deshpande SV, Sharma SD, Nag B. Antigen-specific deletion of cloned T cells using peptide-toxin conjugate complexed with purified class II major histocompatibility complex antigen. J Biol Chem 1994; 269:94-9. [PMID: 7506264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In a previous report, we showed that cloned T cells incubated with soluble, cognate major histocompatibility complex (MHC) II-peptide complex internalized the peptide moiety of the complex. Here, we report antigen-specific deletion of cloned T cells by treatment with soluble, cognate MHC II-(peptide-toxin) complexes. Toxin (doxorubicin or mycophenolic acid) was attached to synthetic AcMBP(1-14)Ala4 peptide, an analog of the natural acetylated NH2-terminal segment, AcMBP(1-14), of rat myelin basic protein (MBP). IAk-restricted, AcMBP(1-14)-Specific AJ1.2 and 4R3.9 cloned murine T cells were killed by IAk-(AcMBP(1-14)Ala4-toxin). No killing resulted from incubating AJ1.2 and 4R3.9 cells with irrelevant MHC II-(peptide-toxin) or treating IEk-restricted, pigeon cytochrome c-specific A.E7 cloned murine T cells with IAk-(AcMBP(1-14)Ala4-toxin). T cell receptor-mediated T cell uptake of the peptide-toxin moiety of relevant complex was blocked by anti-T cell receptor-alpha/beta antibody and by excess toxin-free complex. LD50 determinations revealed that cognate MHC II-(peptide-toxin) killed T cells much more effectively than did peptide-toxin conjugate alone. Finally, T cell uptake of peptide-toxin and intracellular release of toxin occurred after incubation with relevant MHC II-(peptide-toxin) containing radiolabeled toxin. These findings, which provide the first evidence that cloned T cells can be deleted with soluble, cognate MHC II-(peptide-toxin) complexes, may have significant clinical relevance for antigen-specific therapy of autoimmune or other T cell-mediated diseases.
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Affiliation(s)
- B R Clark
- Anergen, Inc., Redwood City, California 94063
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Tolbert DL, Alisky JM, Clark BR. Lower thoracic upper lumbar spinocerebellar projections in rats: a complex topography revealed in computer reconstructions of the unfolded anterior lobe. Neuroscience 1993; 55:755-74. [PMID: 7692349 DOI: 10.1016/0306-4522(93)90440-q] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [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: 01/26/2023]
Abstract
The topography of wheatgerm agglutinin-horseradish peroxidase/horseradish peroxidase-labeled mossy fiber terminals of lower thoracic-upper lumbar (T12-L3) spinal projections to the cerebellar anterior lobe was quantitatively analysed in adult rats. Computer-based image analysis mapped the orthogonal (parallel to the surface) distribution of labeled terminals in two-dimensional reconstructions of the unfoled anterior lobe cortex. The radial (perpendicular to the surface) distribution of terminals within the granule cell layer was mapped by computing whether the terminals were in either the outer- or inner-halves of this layer. The number of labeled terminals in each lobule was calculated. In the anterior lobe, lower thoracic-upper lumbar spinocerebellar projections terminate primarily in lobules II (mean 27.14%), III (mean 38.68%), and IV (mean 19.31%). Different-sized bilateral injections restricted to L1 were used to study the organization of intrasegmental spinocerebellar projections. Small injections into L1 labeled a limited number of terminals which were located either in clusters or were spatially isolated. Intermediate-sized intrasegmental injections resulted in additional clusters of labeled terminals. Many of the terminal clusters were spatially related and formed larger irregularly shaped patches. Large intrasegmental injections labeled terminal clusters and patches that were discontinuous but aligned parallel to the longitudinal (transverse) axis of lobules II-IV. Injections including segments rostral and caudal to L1 were used to study the topography of intersegmental lower thoracic-upper lumbar spinocerebellar projections. Multisegmental injections increased the number of labeled terminal clusters and patches which obscured the pattern of segmental input, but there was still a transversely oriented pattern of termination. Distinct transversely aligned terminal free areas remained apparent. Lower thoracic-upper lumbar spinocerebellar projections terminated in both the outer- and inner-halves of the granule cell layer, but overall were more numerous in the outer-half of this layer. In serially spaced sagittal sections, however, the majority of terminals alternated between the outer- and inner-halves of the granule cell layer. Outer- and inner-terminals were not spatially segregated in their orthogonal distribution. These results indicate lower thoracic-upper lumbar spinocerebellar projections have a complex three-dimensional topography in the anterior lobe. These findings are discussed in relation to previous findings for a sagittally oriented topography for lower thoracic-upper lumbar spinocerebellar projections and in the context of how cerebellar somatosensory afferent input may be organized.
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Affiliation(s)
- D L Tolbert
- Francis and Doris Murphy Neuroanatomy Research Laboratory, St Louis University School of Medicine, Missouri 63104
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Nag B, Deshpande SV, Sharma SD, Clark BR. Cloned T cells internalize peptide from bound complexes of peptide and purified class II major histocompatibility complex antigen. J Biol Chem 1993; 268:14360-6. [PMID: 7686154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Antigen presentation to helper T cells involves the formation of a trimolecular complex consisting of a class II major histocompatibility complex (MHC) antigen combined with an antigenic peptide on the surface of an antigen-presenting cell and a T cell receptor (TCR) on the T cell. The fate of the MHC class II, peptide, or TCR moieties of the ternary complex following antigen presentation is unknown. Using radiolabeled complexes of affinity-purified murine MHC class II molecules and peptides corresponding to T cell epitopes of myelin basic protein (MBP), this report presents evidence that the binding of preformed relevant MHC class II-peptide complexes to cloned T cells in vitro results in internalization of the peptide moiety. Neither the restricting MHC class II molecule nor the TCR moiety of the trimolecular complex was internalized by T cells. The specificity of peptide internalization was demonstrated using complexes of syngeneic MHC class II with an irrelevant MBP peptide analog and by cloned T cells restricted for a different epitope of the same MBP antigen. Furthermore, the peptide translocation mediated by MHC class II and TCR was demonstrated by antibody-blocking experiments using anti-class and anti-TCR monoclonal antibodies. The peptide internalization by T cells was markedly reduced when binding was performed at 4 degrees C as compared with 37 degrees C. In addition, a significant inhibition of peptide translocation was observed in the presence of a metabolic inhibitor (sodium azide) but not in the presence of cytochalasin B. These results together demonstrate that the in vitro interaction of soluble MHC II-peptide complexes with cloned T cells is an active process associated with uptake of the antigenic peptide.
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Affiliation(s)
- B Nag
- Anergen Inc., Redwood City, California 94063
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Nag B, Wada HG, Deshpande SV, Passmore D, Kendrick T, Sharma SD, Clark BR, McConnell HM. Stimulation of T cells by antigenic peptide complexed with isolated chains of major histocompatibility complex class II molecules. Proc Natl Acad Sci U S A 1993; 90:1604-8. [PMID: 7679510 PMCID: PMC45923 DOI: 10.1073/pnas.90.4.1604] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Major histocompatibility complex (MHC) class II molecules are heterodimeric glycoproteins with one alpha and one beta polypeptide chain of similar molecular size. In this report, we describe the binding of an acetylated N-terminal peptide of myelin basic protein, [Ala4]MBP-(1-14), to purified individual alpha and beta chains of murine I-Ak molecules. Purified complexes of isolated single chains and antigenic peptide bind to cloned T cells restricted by I-Ak and [Ala4]MBP-(1-14) tetradecapeptide. The binding is blocked by alpha/beta anti-T-cell receptor (TCR) monoclonal antibody. Cell triggering as measured by an increase in extracellular acidification rate is observed when cloned T cells are exposed to purified complexes of isolated chains and antigenic peptide. This increase in the extracellular acidification rate is antigen specific and MHC-restricted, as chains alone or irrelevant chain-peptide complexes do not trigger an increase in the metabolic acidification rate. These results together demonstrate that in vitro cloned T cells are triggered by complexes of specific antigenic peptides and isolated individual chains of their cognate MHC proteins.
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Affiliation(s)
- B Nag
- Anergen Incorporated, Redwood City, CA 94063
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Nag B, Wada HG, Passmore D, Clark BR, Sharma SD, McConnell HM. Purified beta-chain of MHC class II binds to CD4 molecules on transfected HeLa cells. The Journal of Immunology 1993. [DOI: 10.4049/jimmunol.150.4.1358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The initial event triggering the activation of Th cells occurs when the TCR interacts with antigenic peptide in the context of the MHC II on APC. Various T cell accessory molecules including CD4, CD28, and LFA-1 participate and facilitate the activation event. Although some evidence for the interaction of MHC II and CD4 is available, the site of MHC class II (alpha-chain, beta-chain, or both chains) for CD4 interaction has not yet been clearly defined. Results from different laboratories had indicated the involvement of alpha 1, beta 1, and beta 2 domains of MHC class II molecules in CD4 interaction. Recently, a conserved site of DR beta 2 domain has been identified that involves CD4 interaction that is analogous to MHC class I binding site for CD8 molecule. In this report, direct binding of affinity-purified HLA-DR2 dimer and its isolated alpha- and beta-chains to CD4 was studied using a CD4-transfected HeLa cell line. Preferential binding of the beta-chain and intact MHC II dimer to the CD4-transfected cells was observed and found to be specifically inhibited by anti-CD4 mAb. In contrast, the isolated alpha-chain of HLA DR2 did not show significant binding to CD4-transfected cells. Complexes of radiolabeled DR2 dimer or beta-chain alone with an immunodominant epitope from myelin basic protein (83-102) did not show any further increase in binding of these molecules. Binding of the beta-chain to CD4+ cells was markedly inhibited by a DR beta 1 peptide (35-46) and was partially inhibited by a DR beta 2 peptide (134-148) of MHC class II molecule. These results suggest the involvement of at least two conserved regions of the beta polypeptide chain of MHC class II in CD4 interaction. Because in our experiments transfected cells lack TCR molecules and the binding of DR2 to the CD4-transfected cells was unaffected by added antigenic peptide, it is possible that the interaction of MHC class II to CD4 is independent of TCR occupancy.
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Affiliation(s)
- B Nag
- Anergen Inc., Redwood City, CA 94063
| | - H G Wada
- Anergen Inc., Redwood City, CA 94063
| | | | - B R Clark
- Anergen Inc., Redwood City, CA 94063
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Nag B, Wada HG, Passmore D, Clark BR, Sharma SD, McConnell HM. Purified beta-chain of MHC class II binds to CD4 molecules on transfected HeLa cells. J Immunol 1993; 150:1358-64. [PMID: 8432982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The initial event triggering the activation of Th cells occurs when the TCR interacts with antigenic peptide in the context of the MHC II on APC. Various T cell accessory molecules including CD4, CD28, and LFA-1 participate and facilitate the activation event. Although some evidence for the interaction of MHC II and CD4 is available, the site of MHC class II (alpha-chain, beta-chain, or both chains) for CD4 interaction has not yet been clearly defined. Results from different laboratories had indicated the involvement of alpha 1, beta 1, and beta 2 domains of MHC class II molecules in CD4 interaction. Recently, a conserved site of DR beta 2 domain has been identified that involves CD4 interaction that is analogous to MHC class I binding site for CD8 molecule. In this report, direct binding of affinity-purified HLA-DR2 dimer and its isolated alpha- and beta-chains to CD4 was studied using a CD4-transfected HeLa cell line. Preferential binding of the beta-chain and intact MHC II dimer to the CD4-transfected cells was observed and found to be specifically inhibited by anti-CD4 mAb. In contrast, the isolated alpha-chain of HLA DR2 did not show significant binding to CD4-transfected cells. Complexes of radiolabeled DR2 dimer or beta-chain alone with an immunodominant epitope from myelin basic protein (83-102) did not show any further increase in binding of these molecules. Binding of the beta-chain to CD4+ cells was markedly inhibited by a DR beta 1 peptide (35-46) and was partially inhibited by a DR beta 2 peptide (134-148) of MHC class II molecule. These results suggest the involvement of at least two conserved regions of the beta polypeptide chain of MHC class II in CD4 interaction. Because in our experiments transfected cells lack TCR molecules and the binding of DR2 to the CD4-transfected cells was unaffected by added antigenic peptide, it is possible that the interaction of MHC class II to CD4 is independent of TCR occupancy.
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Affiliation(s)
- B Nag
- Anergen Inc., Redwood City, CA 94063
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Abstract
Haemopoiesis occurs in close physical contact with elements of the bone marrow stroma. This review examines some adhesion molecules which are expressed in haemopoietic environments. These molecules may act to maintain cell contact between haemopoietic progenitors and the cellular and extracellular matrix elements of the marrow stroma. A review is undertaken of several families of adhesion molecules and their ligands, including integrins, CD44, LEC-CAMs, CAMs and variant glycosylation patterns expressed by haemopoietic cells. Both CD44 and integrin receptors have been implicated in mediating important cellular interactions within the haemopoietic system and the significance of these and other molecules in haemopoiesis is discussed.
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Nag B, Wada HG, Fok KS, Green DJ, Sharma SD, Clark BR, Parce JW, McConnell HM. Antigen-specific stimulation of T cell extracellular acidification by MHC class II-peptide complexes. The Journal of Immunology 1992. [DOI: 10.4049/jimmunol.148.7.2040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
A specific T cell response to a preformed complex of detergent-solubilized MHC class II molecule and cognate antigenic peptide was observed by monitoring the extracellular acidification. An increase in this rate was observed when the resting 4R3.9 T cell clone specific for the peptide fragment MBP(1-14) of myelin basic protein was exposed to preformed detergent-solubilized IAk-MBP(1-14)A4 complexes. MBP peptide alone, IAk alone, or complexes of IAs-proteolipid protein(139-151) and IAd-OVA(323-339), did not cause significant increases in the acidification rates of the MBP(1-14)-restricted 4R3.9 T cell clone. In addition, BW 5147 T lymphoma cells, which lack TCR, did not show any increase in rate when exposed to IAk-MBP(1-14)A4 complexes. Similar increases in acidification rate were observed in the presence of IL-2, anti-CD3 and anti-TCR antibodies. The enhanced acidification responses were blocked by genistein, a tyrosine kinase inhibitor.
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Affiliation(s)
- B Nag
- Anergen Incorporation, Redwood City, CA 94063
| | - H G Wada
- Anergen Incorporation, Redwood City, CA 94063
| | - K S Fok
- Anergen Incorporation, Redwood City, CA 94063
| | - D J Green
- Anergen Incorporation, Redwood City, CA 94063
| | - S D Sharma
- Anergen Incorporation, Redwood City, CA 94063
| | - B R Clark
- Anergen Incorporation, Redwood City, CA 94063
| | - J W Parce
- Anergen Incorporation, Redwood City, CA 94063
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Nag B, Wada HG, Fok KS, Green DJ, Sharma SD, Clark BR, Parce JW, McConnell HM. Antigen-specific stimulation of T cell extracellular acidification by MHC class II-peptide complexes. J Immunol 1992; 148:2040-4. [PMID: 1372021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
A specific T cell response to a preformed complex of detergent-solubilized MHC class II molecule and cognate antigenic peptide was observed by monitoring the extracellular acidification. An increase in this rate was observed when the resting 4R3.9 T cell clone specific for the peptide fragment MBP(1-14) of myelin basic protein was exposed to preformed detergent-solubilized IAk-MBP(1-14)A4 complexes. MBP peptide alone, IAk alone, or complexes of IAs-proteolipid protein(139-151) and IAd-OVA(323-339), did not cause significant increases in the acidification rates of the MBP(1-14)-restricted 4R3.9 T cell clone. In addition, BW 5147 T lymphoma cells, which lack TCR, did not show any increase in rate when exposed to IAk-MBP(1-14)A4 complexes. Similar increases in acidification rate were observed in the presence of IL-2, anti-CD3 and anti-TCR antibodies. The enhanced acidification responses were blocked by genistein, a tyrosine kinase inhibitor.
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Affiliation(s)
- B Nag
- Anergen Incorporation, Redwood City, CA 94063
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Nag B, Passmore D, Deshpande SV, Clark BR. In vitro maximum binding of antigenic peptides to murine MHC class II molecules does not always take place at the acidic pH of the in vivo endosomal compartment. The Journal of Immunology 1992. [DOI: 10.4049/jimmunol.148.2.369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Presentation of Ag to the T cell requires binding of specific peptide fragments of the Ag to MHC II molecules. The ability of a peptide to bind to MHC class II appears to be pH dependent. Recent reports indicate that the binding of peptide to MHC class II molecules takes place primarily within an endosomal compartment of the cell at around pH 5. In this study, we have explored the in vitro pH dependence of peptide binding to different haplotypes of murine MHC class II molecules. The binding of peptides to MHC II was analyzed and quantitated by silica gel TLC, using radiolabeled peptides. The MBP peptide fragments, MBP(1-14)A4 and MBP(88-101)Y88, bound maximally at pH 8 to IAk and IAs, respectively. The binding of PLP peptide fragment, PLP(138-151)Y138, to IAs was maximal at around neutral pH. The maximum binding of an OVA peptide fragment, OVA(323-340)Y340, to IAd, was found to occur at pH 6. Results presented in this report thus suggest that the in vitro maximum binding of peptide is pH dependent and does not always occur at pH 5. The optimum pH range for maximum binding may depend on the nature and net charge of the peptide and its interaction with MHC class II molecules.
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Affiliation(s)
- B Nag
- Anergen Inc., Redwood City, CA 94063
| | | | | | - B R Clark
- Anergen Inc., Redwood City, CA 94063
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Nag B, Passmore D, Deshpande SV, Clark BR. In vitro maximum binding of antigenic peptides to murine MHC class II molecules does not always take place at the acidic pH of the in vivo endosomal compartment. J Immunol 1992; 148:369-72. [PMID: 1370312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Presentation of Ag to the T cell requires binding of specific peptide fragments of the Ag to MHC II molecules. The ability of a peptide to bind to MHC class II appears to be pH dependent. Recent reports indicate that the binding of peptide to MHC class II molecules takes place primarily within an endosomal compartment of the cell at around pH 5. In this study, we have explored the in vitro pH dependence of peptide binding to different haplotypes of murine MHC class II molecules. The binding of peptides to MHC II was analyzed and quantitated by silica gel TLC, using radiolabeled peptides. The MBP peptide fragments, MBP(1-14)A4 and MBP(88-101)Y88, bound maximally at pH 8 to IAk and IAs, respectively. The binding of PLP peptide fragment, PLP(138-151)Y138, to IAs was maximal at around neutral pH. The maximum binding of an OVA peptide fragment, OVA(323-340)Y340, to IAd, was found to occur at pH 6. Results presented in this report thus suggest that the in vitro maximum binding of peptide is pH dependent and does not always occur at pH 5. The optimum pH range for maximum binding may depend on the nature and net charge of the peptide and its interaction with MHC class II molecules.
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Affiliation(s)
- B Nag
- Anergen Inc., Redwood City, CA 94063
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Sharma SD, Nag B, Su XM, Green D, Spack E, Clark BR, Sriram S. Antigen-specific therapy of experimental allergic encephalomyelitis by soluble class II major histocompatibility complex-peptide complexes. Proc Natl Acad Sci U S A 1991; 88:11465-9. [PMID: 1722335 PMCID: PMC53156 DOI: 10.1073/pnas.88.24.11465] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Experimental allergic encephalomyelitis is a T-cell-mediated, major histocompatibility complex (MHC) class II gene-linked autoimmune demyelinating disease of the central nervous system. To develop therapies that will specifically inactivate only the autoantigen-reactive T cells, mice were treated with soluble MHC class II molecules that had been complexed with encephalitogenic peptides. Intravenous injections of 300 micrograms of complexes consisting of encephalitogenic peptide 91-103 of myelin basic protein plus I-As protein on day 0, 4, and 7 were effective in preventing experimental allergic encephalomyelitis. Similarly, administration of 45 micrograms of I-As protein complexed to peptide 139-151 from proteolipoprotein on day 1, 4, and 7 prevented mortality and significantly reduced paralysis induced by immunization with the encephalitogenic proteolipoprotein peptide. Histological examination of sections of animal brains revealed that treatment with I-As protein plus myelin basic protein 91-103 peptide prevents the development of inflammatory lesions characteristic of experimental allergic encephalomyelitis. Thus, treatment with MHC-self-peptide complexes could serve as a highly specific therapeutic modality in treating autoimmune disease when the putative autoantigen and the MHC restricting elements are known.
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Abstract
A peptide comprising amino acids 323-339 of chicken ovalbumin is known to bind to two heterodimeric conformations of the MHC molecule IA(d), and to each of its separate alpha- and beta-chains. We report that minor C- and N-terminal truncations of the parent peptide do not alter the binding pattern. A decrease in binding activity was observed upon deletion of the histidine residues of the already truncated peptides. Peptides as short as 4 amino acids associate weakly with all four proteins.
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Affiliation(s)
- K Dornmair
- Stauffer Laboratory for Physical Chemistry, Stanford University, CA 94305
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Abstract
Effects of endotoxin administration on the biological activity of calmodulin isolated from canine heart and liver were studied. Calmodulin was isolated and purified to homogeneity. The biological activity of calmodulin was determined by its ability to activate Ca(2+)-dependent phosphodiesterase. Results obtained 4 h after endotoxin administration show that the Vmax and A0.5 for calmodulin, the Vmax and Km for cAMP, and the Vmax and the Hill coefficient for Ca2+ were unchanged, while the S0.5 for Ca2+ for the activation of phosphodiesterase were significantly increased in the heart. The kinetic parameters as described above were not significantly altered in the liver. These data indicate that the biological activity of calmodulin is inhibited in the heart during endotoxin shock and that the nature of inhibition is associated with a mechanism involving a decrease in the affinity (1/S0.5) towards Ca2+ binding. Since calmodulin plays an important role in the regulation of cardiac function through calmodulin-dependent calcium transport systems, our findings may have a pathophysiological significance in contributing to the understanding of myocardial dysfunction in endotoxin shock.
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Affiliation(s)
- B R Clark
- Department of Pharmacological and Physiological Science, St. Louis University School of Medicine, MO 63104
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Abstract
The 17-amino acid peptide from chicken ovalbumin, Ova(323-339), was labeled at the amino terminus with fluorescein [FOva(323-339)] and near the carboxyl terminus with Texas Red [AcOva(323-338)KTR]. Fluorescence spectroscopy was carried out on resolved electrophoretic bands on nonreducing polyacrylamide gels derived from incubation mixtures containing major histocompatibility complex (MHC) class II molecules IAd and the FOva(323-339)- and AcOva(323-338)KTR-labeled peptides. Energy transfer between fluorescein and Texas Red was observed in the "floppy" alpha beta heterodimer band, but not in the "compact" alpha beta heterodimer band. Energy transfer was detected between the truncated peptides FOva(323-328)CONH2 and AcOva(331-338)KTR in both the compact alpha beta and floppy alpha beta gel bands. The energy-transfer data suggest that the two binding sites of floppy alpha beta arise from splitting apart a putative large, single binding site region in compact alpha beta.
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Affiliation(s)
- R Tampé
- Stauffer Laboratory for Physical Chemistry, Stanford University, CA 94305
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Abstract
One of the important steps for antigen presentation by MHC class II molecules involves binding of a peptide fragment of the antigen to the class II molecule followed by recognition of the resulting complex by T cells. The most commonly used methods for studying binding of peptide to MHC II are: equilibrium dialysis, gel filtration chromatography, HPLC and polyacrylamide gel electrophoresis. Each of these methods has some limitations and is time consuming. In addition, each requires a considerable amount of native MHC class II, which is always difficult to obtain. In this report, we describe three different sensitive methods using radiolabeled peptide to study peptide binding to murine MHC class II molecules. These are: nitrocellulose filter binding, thin-layer chromatography (TLC) using plate-supported silica gel or PEI cellulose, and paper electrophoresis using Sepraphor cellulose polyacetate paper. All three methods are rapid, highly sensitive and require only ng quantities of affinity pure MHC class II molecules and peptides. These methods can be used to calculate the peptide occupancy of MHC class II molecules.
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Affiliation(s)
- B Nag
- Biospan Corporation, Redwood City, CA 94063
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46
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Kelly SE, Hunter JA, Jones DB, Clark BR, Fleming S. Morphological evidence for calcium-dependent association of calgranulin with the epidermal cytoskeleton in inflammatory dermatoses. Br J Dermatol 1991; 124:403-9. [PMID: 2039714 DOI: 10.1111/j.1365-2133.1991.tb00616.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The association of calgranulins, intracellular calcium-binding proteins, with the keratinocyte cytoskeleton has been studied. These molecules are expressed in various inflammatory dermatoses and in organ-culture explants. Triton X-100 extraction in the presence of calcium or EDTA suggested that calgranulins are detergent insoluble in the presence of calcium. The molecules were localized in a plaque-like structure at the cell periphery in lesional skin and in organ-culture explants. Following induction of calgranulins in vitro there was a redistribution of the intermediate filament cytoskeleton into a perinuclear halo, although desmosomes remained intact. These various features suggest that these members of the S-100 protein family have a role in cytoskeletal changes seen in various skin diseases.
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Affiliation(s)
- S E Kelly
- Department of Dermatology, University of Edinburgh, U.K
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47
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Clark BR. Asians and UCLA Admission. Science 1991; 251:144. [PMID: 17836925 DOI: 10.1126/science.251.4990.144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Abstract
The molecules calgranulin A and B are two intracellular calcium-binding proteins which are expressed by the lesional keratinocytes of inflammatory dermatoses. We have investigated the induction of the calgranulin proteins in an in vitro system and characterized the epidermal form of calgranulin. Using calgranulin-specific monoclonal antibodies, we have shown that these proteins are expressed within the epidermis of skin explants after 12-24 h culture in vitro. The induction of calgranulin-specific staining on culture was prevented, however, by the inclusion of cycloheximide in the culture medium, in sufficient quantities to prevent de novo protein synthesis. Indirect immunofluorescence staining was used to analyse the subcellular localization of the calgranulin proteins. The specific staining pattern with antibodies which recognize the individual calgranulin proteins was retained in detergent insoluble cytoskeletal preparations of epidermis. In Western blotting experiments epidermal calgranulins could be solubilized only by using a urea-based protein extraction buffer. After sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis of the epidermal extracts a single antigen, with a molecular weight of 13.0 kD was detected with the calgranulin-specific antibody MAC 387. The expression of calgranulins, similar to other members of the same protein family, may regulate cytoskeletal changes in skin disease.
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Affiliation(s)
- B R Clark
- Department of Pathology, University of Edinburgh, U.K
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Abstract
We have determined the map position of a viral gene encoding a 32-kDa late structural protein of human cytomegalovirus (HCMV) using a murine monoclonal antibody. This monoclonal antibody was reactive with two protein bands of 32 and 27 kDa in HCMV-infected cell lysates and with a single 32-kDa protein band in HCMV virions as detected by immunoblot analysis. When purified HCMV envelope preparation was used for immunoblotting, the monoclonal antibody did not display a detectable band. We used this monoclonal antibody to screen a cDNA library that was constructed from poly(A)+ RNA of late HCMV-infected cells and cloned into the expression vector lambda gt11. A cDNA clone that expressed an immunoreactive epitope of the late HCMV protein fused to beta-galactosidase was identified. Probing the restriction digests of HCMV (Towne and AD169) DNA with insert DNA from the immunoreactive lambda gt11 clone permitted us to localize the coding sequence within the long unique region between map coordinates of 0.62 and 0.64 of HCMV Towne and AD169 genomes. Using the same probe, a single transcript of 1.4 kb was detected in total RNA from HCMV-infected cells at late times after infection.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- Blotting, Northern
- Blotting, Southern
- Capsid/genetics
- Capsid/immunology
- Centrifugation, Density Gradient
- Cloning, Molecular
- Cytomegalovirus/genetics
- DNA Probes
- DNA Restriction Enzymes
- DNA, Viral/analysis
- Electrophoresis, Agar Gel
- Electrophoresis, Polyacrylamide Gel
- Enzyme-Linked Immunosorbent Assay
- Genes, Viral
- Humans
- Hybridomas
- Immunoblotting
- Nucleic Acid Hybridization
- RNA, Viral/analysis
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Affiliation(s)
- H Pande
- Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, California 91010
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