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Lee J, Nakamura T, Kobayashi K, Kim DT, Ha T, Hahn GR, Kim KJ, Shin S. Transverse bunch-by-bunch feedback system for time-resolved experiments at PLS-II. J Synchrotron Radiat 2021; 28:1417-1422. [PMID: 34475289 DOI: 10.1107/s1600577521005889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/07/2021] [Indexed: 06/13/2023]
Abstract
A description of the upgraded bunch-by-bunch feedback system for time-resolved experiments at Pohang Light Source II (PLS-II) is provided. The bunch-by-bunch feedback system has been upgraded to increase the single-bunch current in the hybrid fill pattern of the PLS-II facility. The project is part of the SPring-8 and PLS-II collaboration. The main features of the upgrade are to employ a single 500 MHz analog-to-digital converter (ADC) instead of the previous four 125 MHz interleaved ADCs for 500 MHz rate, to replace a single-loop two-dimensional feedback with two independent one-dimensional feedback loops, to implement the tune measurement function with a single bunch, and mainly to implement single-bunch and stretcher control. The realization of a 400 mA hybrid fill pattern including a 10 mA single bunch demonstrates the precision of the upgraded bunch-by-bunch feedback system.
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Affiliation(s)
- Jaeyu Lee
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - T Nakamura
- SPring-8, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - K Kobayashi
- SPring-8, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - D T Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - T Ha
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - G R Hahn
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - K J Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - S Shin
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
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Lee J, Chun MH, Kim GJ, Shin DC, Kim DT, Shin S. Bunch-by-bunch position measurement and analysis at PLS-II. J Synchrotron Radiat 2017; 24:163-167. [PMID: 28009555 DOI: 10.1107/s1600577516018154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/11/2016] [Indexed: 06/06/2023]
Abstract
A bunch-by-bunch measurement system has been developed at Pohang Light Source II. The system consists of a four-channel button pick-up, 20 GHz sampling oscilloscope and an 800 MHz low-pass digital filter. Upon measuring a bunch-by-bunch spatio-temporal beam motion matrix over many turns, singular-value decomposition analysis is used to reveal the dominant coupled-bunch modes. The system can diagnose injection oscillations due to kicker errors and the effect of resistive-wall impedance that gives rise to instability during operation.
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Affiliation(s)
- Jaeyu Lee
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - M H Chun
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - G J Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - D C Shin
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - D T Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - S Shin
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
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Onifer SM, Rodríguez JF, Santiago DI, Benitez JC, Kim DT, Brunschwig JP, Pacheco JT, Perrone JV, Llorente O, Hesse DH, Martinez-Arizala A. Cervical spinal cord injury in the adult rat: assessment of forelimb dysfunction. Restor Neurol Neurosci 2012; 11:211-23. [PMID: 21551865 DOI: 10.3233/rnn-1997-11405] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Traumatic injury to the adult human spinal cord most frequently occurs at the mid-to-low cervical segments and produces tetraplegia. To investigate treatments for improving upper extremity function after cervical spinal cord injury (SCI), three behavioral tests were examined for their potential usefulness in evaluating forelimb function in an adult rat model that mimics human low cervical SCI. Testing was conducted pre- and up to 4 weeks post-operation in adult female rats subjected to either contusion injury at the C7 spinal cord segment or sham-surgery. Modified Forelimb Tarlov scales revealed significant proximal and distal forelimb extension dysfunction in lesion rats at l-to-4 weeks post-cervical SCI. The Forelimb Grip Strength Test showed a significant decrease in forelimb grip strength of lesion rats throughout the 4 weeks post-cervical SCI. Significant deficits in reach and pellet retrieval by lesion rats were measured at l-to-4 weeks post-cervical SCI with the conditioned pellet retrieval Staircase Test. The results demonstrate that these qualitative and quantitative forelimb behavioral tests can be used to evaluate forelimb function following low cervical SCI and may be useful to investigate treatments for improving forelimb function in these lesions.
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Affiliation(s)
- S M Onifer
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami School of Medicine, Miami, FL 33136
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Abstract
Homopolymers or peptides containing a high percentage of cationic amino acids have been shown to have a unique ability to cross the plasma membrane of cells, and consequently have been used to facilitate the uptake of a variety of biopolymers and small molecules. To investigate whether the polycationic character of these molecules, or some other structural feature, was the molecular basis for the effect, the ability of a variety of homopolymers to enter cells was assayed by confocal microscopy and flow cytometry. Polymers of L- or D-arginine containing six or more amino acids entered cells far more effectively than polymers of equal length composed of lysine, ornithine and histidine. Peptides of fewer than six amino acids were ineffective. The length of the arginine side-chain could be varied without significant loss of activity. These data combined with the inability of polymers of citrulline to enter cells demonstrated that the guanidine headgroup of arginine was the critical structural component responsible for the biological activity. Cellular uptake could be inhibited by preincubation of the cells with sodium azide, but not by low temperature (3 degrees C), indicating that the process was energy dependent, but did not involve endocytosis.
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Affiliation(s)
- D J Mitchell
- Department of Neurology, Stanford University, USA
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Kim DT, Lai AC, Hwang C, Fan LT, Karagueuzian HS, Chen PS, Fishbein MC. The ligament of Marshall: a structural analysis in human hearts with implications for atrial arrhythmias. J Am Coll Cardiol 2000; 36:1324-7. [PMID: 11028490 DOI: 10.1016/s0735-1097(00)00819-6] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES We sought to study the anatomy of human ligament of Marshall (LOM). BACKGROUND Although the LOM has been implicated in the genesis of focal atrial tachyarrhythmias, its gross anatomic and microscopic features in humans hearts have not been completely defined. METHODS We studied seven postmortem human hearts from five men and two women with a mean age of 52 +/- 26 years. Four did not have any heart disease. One woman had dilated cardiomyopathy, and two men had chronic atrial fibrillation. A block of tissue encompassing the LOM from the coronary sinus (CS) cephalad, between the atrial appendage and left pulmonary veins, was dissected. Serial sections from this tissue were then stained with hematoxylin and eosin, trichrome, and/or tyrosine hydroxylase. RESULTS The LOM consists of multiple sympathetic nerve fibers, ganglia, blood vessels and multiple myocardial tracts (Marshall Bundles) insulated by fibrofatty tissue. One or more myocardial tracts was inserted directly into the left atrial free wall and CS. The distance between insertion sites was 7.8 +/- 2.5 mm. Nerve fibers, some tyrosine hydroxylase positive, were present within the fibrofatty matrix and within the myocardial tracts. CONCLUSIONS Human LOM 1) is innervated by sympathetic nerve fibers; 2) is more complex than the LOM in canine hearts; and 3) has multiple myocardial tract insertions into the left atrial free wall and CS, forming a substrate of reentry. Radiofrequency catheter ablation from the CS may fail to reach the free wall insertion.
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Affiliation(s)
- D T Kim
- Department of Medicine at Cedars-Sinai Medical Center/UCLA, Los Angeles, California, USA
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Kim DT, Mitchell DJ, Brockstedt DG, Fong L, Nolan GP, Fathman CG, Engleman EG, Rothbard JB. Introduction of soluble proteins into the MHC class I pathway by conjugation to an HIV tat peptide. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.159.4.1666] [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: 01/02/2023]
Abstract
Abstract
Protection against most intracellular pathogens requires T cells that recognize pathogen-derived peptides in association with MHC class I molecules on the surface of infected cells. However, because exogenous proteins do not ordinarily enter the cytosol and access the MHC class I-processing pathway, protein-based vaccines that induce class I-restricted CTL responses have proved difficult to design. We have addressed this problem by conjugating proteins, such as OVA, to a short cationic peptide derived from HIV-1 tat (residues 49-57). When APC were exposed in vitro to such protein conjugates, they processed and presented the peptides in association with MHC class I molecules and stimulated CD8+ Ag-specific T cells. Moreover, Ag-specific CTLs were generated in vivo by immunizing mice with histocompatible dendritic cells that had been exposed to protein-tat conjugates.
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Affiliation(s)
- D T Kim
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - D J Mitchell
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - D G Brockstedt
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - L Fong
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - G P Nolan
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - C G Fathman
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - E G Engleman
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - J B Rothbard
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
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Kim DT, Mitchell DJ, Brockstedt DG, Fong L, Nolan GP, Fathman CG, Engleman EG, Rothbard JB. Introduction of soluble proteins into the MHC class I pathway by conjugation to an HIV tat peptide. J Immunol 1997; 159:1666-8. [PMID: 9257826] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Protection against most intracellular pathogens requires T cells that recognize pathogen-derived peptides in association with MHC class I molecules on the surface of infected cells. However, because exogenous proteins do not ordinarily enter the cytosol and access the MHC class I-processing pathway, protein-based vaccines that induce class I-restricted CTL responses have proved difficult to design. We have addressed this problem by conjugating proteins, such as OVA, to a short cationic peptide derived from HIV-1 tat (residues 49-57). When APC were exposed in vitro to such protein conjugates, they processed and presented the peptides in association with MHC class I molecules and stimulated CD8+ Ag-specific T cells. Moreover, Ag-specific CTLs were generated in vivo by immunizing mice with histocompatible dendritic cells that had been exposed to protein-tat conjugates.
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Affiliation(s)
- D T Kim
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
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Kim DT, Rothbard JB, Bloom DD, Fathman CG. Quantitative analysis of T cell activation: role of TCR/ligand density and TCR affinity. The Journal of Immunology 1996. [DOI: 10.4049/jimmunol.156.8.2737] [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
(B6 X A)F1 mice were immunized with sperm whale myoglobin, and T cell clones and hybridomas were generated. Hybridoma 74a.e9 was specific for the sperm whale myoglobin 67-79 peptide and could be partially activated by a peptide analogue, equine myoglobin with a natural 74G substitution. Using this hybridoma in T cell activation assays, we studied the effects of varying the avidity of the TCR for its ligand, the concentration of MHC:peptide complex on the APC, and the density of TCR on the surface. Varying ligand concentration on the surface of the APC, the TCR avidity, or the density of TCR on the T cell were equally important parameters in driving T cell activation. The mouse myoglobin (74T) analogue, however, acted as an antagonist to the T cell response. Its effectiveness was also partially determined by its ability to bind to MHC. By independently altering each of these variables and following T cell activation, we describe the interrelationships among these three components (MHC:peptide:TCR) that control the activation of the T cell.
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Affiliation(s)
- D T Kim
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - J B Rothbard
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - D D Bloom
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
| | - C G Fathman
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
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Kim DT, Rothbard JB, Bloom DD, Fathman CG. Quantitative analysis of T cell activation: role of TCR/ligand density and TCR affinity. J Immunol 1996; 156:2737-42. [PMID: 8609391] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
(B6 X A)F1 mice were immunized with sperm whale myoglobin, and T cell clones and hybridomas were generated. Hybridoma 74a.e9 was specific for the sperm whale myoglobin 67-79 peptide and could be partially activated by a peptide analogue, equine myoglobin with a natural 74G substitution. Using this hybridoma in T cell activation assays, we studied the effects of varying the avidity of the TCR for its ligand, the concentration of MHC:peptide complex on the APC, and the density of TCR on the surface. Varying ligand concentration on the surface of the APC, the TCR avidity, or the density of TCR on the T cell were equally important parameters in driving T cell activation. The mouse myoglobin (74T) analogue, however, acted as an antagonist to the T cell response. Its effectiveness was also partially determined by its ability to bind to MHC. By independently altering each of these variables and following T cell activation, we describe the interrelationships among these three components (MHC:peptide:TCR) that control the activation of the T cell.
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MESH Headings
- Amino Acids/pharmacology
- Animals
- Antibodies, Monoclonal/pharmacology
- Binding, Competitive/immunology
- Female
- Histocompatibility Antigens Class II/immunology
- Hybridomas
- Lymphocyte Activation/drug effects
- Major Histocompatibility Complex/drug effects
- Mice
- Mice, Inbred A
- Mice, Inbred C57BL
- Myoglobin/analogs & derivatives
- Myoglobin/chemistry
- Myoglobin/pharmacology
- Peptides/immunology
- Peptides/pharmacology
- Protein Binding/drug effects
- Protein Binding/immunology
- Receptors, Antigen, T-Cell/antagonists & inhibitors
- Receptors, Antigen, T-Cell/chemistry
- Receptors, Antigen, T-Cell/physiology
- T-Lymphocytes/chemistry
- T-Lymphocytes/metabolism
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Affiliation(s)
- D T Kim
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA
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Rohane PW, Shimada A, Kim DT, Edwards CT, Charlton B, Shultz LD, Fathman CG. Islet-infiltrating lymphocytes from prediabetic NOD mice rapidly transfer diabetes to NOD-scid/scid mice. Diabetes 1995; 44:550-4. [PMID: 7729614 DOI: 10.2337/diab.44.5.550] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In an effort to study the development of diabetes in NOD mice, our laboratory developed a novel adoptive transfer model using NOD-scid/scid (NOD-scid) mice as recipients of islet-infiltrating lymphocytes from donor prediabetic female NOD mice. We first confirmed previous results that demonstrated that splenocytes of diabetic and prediabetic female NOD mice could transfer diabetes to NOD-scid mice. We demonstrated that the kinetics of disease transfer were dependent on the age of transferred lymphocytes and reiterated the kinetics of diabetes in conventional female NOD mice. We then demonstrated that islet-infiltrating lymphocytes from prediabetic female NOD mice could transfer diabetes. In contrast with the age-dependent transfer of diabetes seen using splenocytes, islet-infiltrating lymphocytes obtained from prediabetic female NOD mice aged > or = 40 days rapidly transferred diabetes to NOD-scid recipients. The time required to transfer insulin-dependent diabetes mellitus (IDDM) using islet-infiltrating lymphocytes from young prediabetic mice (25 +/- 9 days) was not statistically different from the time required to transfer IDDM using splenocytes from overtly diabetic mice (32 +/- 5 days). Cotransfer of splenocyte cells or CD4+, but not CD8+ spleen cells, from 60- to 80-day-old prediabetic female NOD mice together with either splenocytes from diabetic mice or islet-infiltrating lymphocytes from prediabetic NOD mice delayed the rapid transfer of IDDM, suggesting that CD4+ cells mediated immunoregulation. Use of the NOD-scid islet-infiltrating lymphocyte-adoptive transfer model should help elucidate the pathophysiology of the early inflammatory events leading to insulitis and subsequent beta-cell destruction.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P W Rohane
- Stanford University School of Medicine, California 94305-5111, USA
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Cone DC, Kim DT, Davidson SJ. Patient-initiated refusals of prehospital care: ambulance call report documentation, patient outcome, and on-line medical command. Prehosp Disaster Med 1995; 10:3-9. [PMID: 10155403 DOI: 10.1017/s1049023x0004156x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [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: 11/06/2022]
Abstract
INTRODUCTION There is a growing interest in cases in which emergency medical services (EMS) providers evaluate a patient, but do not transport the patient to a hospital. A subset of these cases, the patient-initiated refusal (PIR) in which the patient refused care and transport, was studied and evaluated. The objectives of the study were to examine the adequacy of ambulance call report documentation in PIR, to examine the clinical outcome of these patients in one hospital-based, suburban EMS system, and to assess the potential impact of on-line medical command (OLMC) on cases of PIR. METHODS The system studied is a hospital-based, transport-capable, advanced life support service in a suburban EMS system, with an annual call volume of 4,200 runs. During the 6-month study period, all ambulance call reports completed by the paramedics and medical command control forms completed by medical command physicians were examined, and cases of PIR collected. Each ambulance call report was examined for adequacy of documentation. Patient outcome was determined from emergency department records and telephone follow-up. RESULTS Eighty-five PIRs were documented during the study period. Four cases were excluded because of a missing ambulance call reports and/or medical command control forms, leaving 81 PIRs for analysis. Despite policy requiring OLMC in cases of PIR, OLMC was established in only 23 PIRs (28%). Of these, two (9%) had inadequate ambulance call report documentation. Of the 58 PIR in which OLMC was not established, 25 (43%) had inadequate ambulance call report documentation (p < 0.001, Fisher's exact test). Follow-up was obtained for 54 (67%) PIR. Of these, 37 (68%) did not subsequently see a physician, and all needed no further medical care. Seven (13%) saw their own physicians within a few days of the initial refusal of prehospital care, and had no further problems. Ten patients were seen in an emergency department within a few days. Three (6%) were discharged, and did well. Seven (13%) were admitted to the hospital, with four (7%) admitted to monitored beds, and three (6%) to unmonitored beds. There were no deaths. CONCLUSIONS Ambulance call report documentation is better with OLMC than without. Patients who initially refuse care may be ill, and some ultimately will be hospitalized. Further research may elucidate a role for OLMC in preventing refusals by incompetent patients, convincing patients who are competent but appear ill to accept transport, and assisting paramedics with other difficult or unusual circumstances.
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Affiliation(s)
- D C Cone
- Department of Emergency Medicine, Medical College of Pennsylvania, Philadelphia 19129-1121, USA
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Abstract
STUDY OBJECTIVE To assess the frequency of institutional review board (IRB) review and informed consent in emergency medical services (EMS) research. DESIGN Two-year, retrospective review of published EMS research. MEASUREMENTS AND MAIN RESULTS One hundred two studies were analyzed. Seventy-one (70%) were exempt from IRB review; 31 (30%) were not exempt. Seventeen nonexempt studies (55%) did not obtain IRB review. Eight of these did not specify a consent method; one used implied consent and eight used volunteers. Volunteers gave informed consent in one study. Of the 14 nonexempt studies with IRB approval, seven did not specify a consent method. Two used informed consent, one received an informed consent waiver, one used verbal consent, and three involved volunteers. Written parent permission was used once when volunteers were minors. CONCLUSION IRB review is often omitted by EMS investigators. This raises ethical concerns about EMS research. Investigators should document their consent method or approval to use an informed consent waiver in their manuscripts. A consent method should be specified for volunteers.
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Affiliation(s)
- D T Kim
- Department of Emergency Medicine, Medical College of Pennsylvania, Philadelphia
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