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Di Mascio M, Srinivasula S, Kim I, Duralde G, St Claire A, DeGrange P, St Claire M, Reimann KA, Gabriel EE, Carrasquillo J, Reba RC, Paik C, Lane HC. Total body CD4+ T cell dynamics in treated and untreated SIV infection revealed by in vivo imaging. JCI Insight 2018; 3:97880. [PMID: 29997291 DOI: 10.1172/jci.insight.97880] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 05/29/2018] [Indexed: 11/17/2022] Open
Abstract
The peripheral blood represents only a small fraction of the total number of lymphocytes in the body. To develop a more thorough understanding of T cell dynamics, including the effects of SIV/SHIV/HIV infection on immune cell depletion and immune reconstitution following combination antiretroviral therapy (cART), one needs to utilize approaches that allow direct visualization of lymphoid tissues. In the present study, noninvasive in vivo imaging of the CD4+ T cell pool has revealed that the timing of the CD4+ T cell pool reconstitution following initiation of ART in SIV-infected nonhuman primates (NHPs) appears seemingly stochastic among clusters of lymph nodes within the same host. At 4 weeks following initiation or interruption of cART, the changes observed in peripheral blood (PB) are primarily related to changes in the whole-body CD4 pool rather than changes in lymphocyte trafficking. Lymph node CD4 pools in long-term antiretroviral-treated and plasma viral load-suppressed hosts appear suboptimally reconstituted compared with healthy controls, while splenic CD4 pools appear similar between the 2 groups.
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Affiliation(s)
- Michele Di Mascio
- AIDS Imaging Research Section, Division of Clinical Research, NIAID, NIH, Bethesda, Maryland, USA
| | - Sharat Srinivasula
- Clinical Research Directorate/Clinical Monitoring Research Program, Leidos Biomedical Research Inc., NCI Campus at Frederick, Frederick, Maryland, USA
| | - Insook Kim
- Applied/Developmental Research Directorate, Leidos Biomedical Research Inc., NCI Campus at Frederick, Frederick, Maryland, USA
| | - Gorka Duralde
- AIDS Imaging Research Section, Division of Clinical Research, NIAID, NIH, Bethesda, Maryland, USA
| | - Alexis St Claire
- AIDS Imaging Research Section, Division of Clinical Research, NIAID, NIH, Bethesda, Maryland, USA
| | - Paula DeGrange
- Battelle/Charles River-Integrated Research Facility, NIAID Frederick, Frederick, Maryland, USA
| | - Marisa St Claire
- AIDS Imaging Research Section, Division of Clinical Research, NIAID, NIH, Bethesda, Maryland, USA
| | - Keith A Reimann
- MassBiologics, University of Massachusetts Medical School, Boston, Massachusetts, USA
| | - Erin E Gabriel
- AIDS Imaging Research Section, Division of Clinical Research, NIAID, NIH, Bethesda, Maryland, USA
| | - Jorge Carrasquillo
- Molecular Imaging and Therapy Service, Radiology Department, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Richard C Reba
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center NIH, Bethesda, Maryland, USA
| | - Chang Paik
- Radiopharmaceutical Laboratory, Nuclear Medicine, Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, Maryland, USA
| | - Henry C Lane
- Laboratory of Immunoregulation, Division of Intramural Research, NIAID, NIH, Bethesda, Maryland, USA
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Dyall J, Johnson RF, Chefer S, Leyson C, Thomasson D, Seidel J, Ragland DR, Byrum R, Jett C, Cann JA, St Claire M, Jagoda E, Reba RC, Hammoud D, Blaney JE, Jahrling PB. [ 18F]-Fluorodeoxyglucose Uptake in Lymphoid Tissue Serves as a Predictor of Disease Outcome in the Nonhuman Primate Model of Monkeypox Virus Infection. J Virol 2017; 91:e00897-17. [PMID: 28814515 PMCID: PMC5640857 DOI: 10.1128/jvi.00897-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/14/2017] [Indexed: 11/20/2022] Open
Abstract
Real-time bioimaging of infectious disease processes may aid countermeasure development and lead to an improved understanding of pathogenesis. However, few studies have identified biomarkers for monitoring infections using in vivo imaging. Previously, we demonstrated that positron emission tomography/computed tomography (PET/CT) imaging with [18F]-fluorodeoxyglucose (FDG) can monitor monkeypox disease progression in vivo in nonhuman primates (NHPs). In this study, we investigated [18F]-FDG-PET/CT imaging of immune processes in lymphoid tissues to identify patterns of inflammation in the monkepox NHP model and to determine the value of [18F]-FDG-PET/CT as a biomarker for disease and treatment outcomes. Quantitative analysis of [18F]-FDG-PET/CT images revealed differences between moribund and surviving animals at two sites vital to the immune response to viral infections, bone marrow and lymph nodes (LNs). Moribund NHPs demonstrated increased [18F]-FDG uptake in bone marrow 4 days postinfection compared to surviving NHPs. In surviving, treated NHPs, increase in LN volume correlated with [18F]-FDG uptake and peaked 10 days postinfection, while minimal lymphadenopathy and higher glycolytic activity were observed in moribund NHPs early in infection. Imaging data were supported by standard virology, pathology, and immunology findings. Even with the limited number of subjects, imaging was able to differentiate the difference between disease outcomes, warranting additional studies to demonstrate whether [18F]-FDG-PET/CT can identify other, subtler effects. Visualizing altered metabolic activity at sites involved in the immune response by [18F]-FDG-PET/CT imaging is a powerful tool for identifying key disease-specific time points and locations that are most relevant for pathogenesis and treatment.IMPORTANCE Positron emission tomography and computed tomography (PET/CT) imaging is a universal tool in oncology and neuroscience. The application of this technology to infectious diseases is far less developed. We used PET/CT imaging with [18F]-labeled fluorodeoxyglucose ([18F]-FDG) in monkeys after monkeypox virus exposure to monitor the immune response in lymphoid tissues. In lymph nodes of surviving monkeys, changes in [18F]-FDG uptake positively correlated with enlargement of the lymph nodes and peaked on day 10 postinfection. In contrast, the bone marrow and lymph nodes of nonsurvivors showed increased [18F]-FDG uptake by day 4 postinfection with minimal lymph node enlargement, indicating that elevated cell metabolic activity early after infection is predictive of disease outcome. [18F]-FDG-PET/CT imaging can provide real-time snapshots of metabolic activity changes in response to viral infections and identify key time points and locations most relevant for monitoring the development of pathogenesis and for potential treatment to be effective.
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Affiliation(s)
- Julie Dyall
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Reed F Johnson
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Svetlana Chefer
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Christopher Leyson
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - David Thomasson
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Jurgen Seidel
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Dan R Ragland
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Russell Byrum
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Catherine Jett
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Jennifer A Cann
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Marisa St Claire
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Elaine Jagoda
- Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Richard C Reba
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Dima Hammoud
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Joseph E Blaney
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
- Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Peter B Jahrling
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
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Chefer S, Thomasson D, Seidel J, Reba RC, Bohannon JK, Lackemeyer MG, Bartos C, Sayre PJ, Bollinger L, Hensley LE, Jahrling PB, Johnson RF. Modeling [(18)F]-FDG lymphoid tissue kinetics to characterize nonhuman primate immune response to Middle East respiratory syndrome-coronavirus aerosol challenge. EJNMMI Res 2015; 5:65. [PMID: 26573211 PMCID: PMC4646887 DOI: 10.1186/s13550-015-0143-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/05/2015] [Indexed: 12/23/2022] Open
Abstract
Background The pathogenesis and immune response to Middle East respiratory syndrome (MERS) caused by a recently discovered coronavirus, MERS-CoV, have not been fully characterized because a suitable animal model is currently not available. 18F-Fluorodeoxyglucose ([18F]-FDG)-positron emission tomography/computed tomography (PET/CT) as a longitudinal noninvasive approach can be beneficial in providing biomarkers for host immune response. [18F]-FDG uptake is increased in activated immune cells in response to virus entry and can be localized by PET imaging. We used [18F]-FDG-PET/CT to investigate the host response developing in nonhuman primates after MERS-CoV exposure and applied kinetic modeling to monitor the influx rate constant (Ki) in responsive lymphoid tissue. Methods Multiple [18F]-FDG-PET and CT images were acquired on a PET/CT clinical scanner modified to operate in a biosafety level 4 environment prior to and up to 29 days after MERS-CoV aerosol exposure. Time activity curves of various lymphoid tissues were reconstructed to follow the [18F]-FDG uptake for approximately 60 min (3,600 s). Image-derived input function was used to calculate Ki for lymphoid tissues by Patlak plot. Results Two-way repeated measures analysis of variance revealed alterations in Ki that was associated with the time point (p < 0.001) after virus exposure and the location of lymphoid tissue (p = 0.0004). As revealed by a statistically significant interaction (p < 0.0001) between these two factors, the pattern of Ki changes over time differed between three locations but not between subjects. A distinguished pattern of statistically significant elevation in Ki was observed in mediastinal lymph nodes (LNs) that correlated to Ki changes in axillary LNs. Changes in LNs Ki were concurrent with elevations of monocytes in peripheral blood. Conclusions [18F]-FDG-PET is able to detect subtle changes in host immune response to contain a subclinical virus infection. Full quantitative analysis is the preferred approach rather than semiquantitative analysis using standardized uptake value for detection of the immune response to the virus. Electronic supplementary material The online version of this article (doi:10.1186/s13550-015-0143-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Svetlana Chefer
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA.
| | - David Thomasson
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Jurgen Seidel
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Richard C Reba
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA.,Present address: Visiting Scientist, Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - J Kyle Bohannon
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Mathew G Lackemeyer
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Chris Bartos
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Philip J Sayre
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Laura Bollinger
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Lisa E Hensley
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Peter B Jahrling
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA.,Emerging Viral Pathogens Section, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Reed F Johnson
- Emerging Viral Pathogens Section, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
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Drozdovitch V, Brill AB, Mettler FA, Beckner WM, Goldsmith SJ, Gross MD, Hays MT, Kirchner PT, Langan JK, Reba RC, Smith GT, Bouville A, Linet MS, Melo DR, Lee C, Simon SL. Nuclear medicine practices in the 1950s through the mid-1970s and occupational radiation doses to technologists from diagnostic radioisotope procedures. Health Phys 2014; 107:300-10. [PMID: 25162420 PMCID: PMC4147674 DOI: 10.1097/hp.0000000000000107] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Data on occupational radiation exposure from nuclear medicine procedures for the time period of the 1950s through the 1970s is important for retrospective health risk studies of medical personnel who conducted those activities. However, limited information is available on occupational exposure received by physicians and technologists who performed nuclear medicine procedures during those years. To better understand and characterize historical radiation exposures to technologists, the authors collected information on nuclear medicine practices in the 1950s, 1960s, and 1970s. To collect historical data needed to reconstruct doses to technologists, a focus group interview was held with experts who began using radioisotopes in medicine in the 1950s and the 1960s. Typical protocols and descriptions of clinical practices of diagnostic radioisotope procedures were defined by the focus group and were used to estimate occupational doses received by personnel, per nuclear medicine procedure, conducted in the 1950s to 1960s using radiopharmaceuticals available at that time. The radionuclide activities in the organs of the reference patient were calculated using the biokinetic models described in ICRP Publication 53. Air kerma rates as a function of distance from a reference patient were calculated by Monte Carlo radiation transport calculations using a hybrid computational phantom. Estimates of occupational doses to nuclear medicine technologists per procedure were found to vary from less than 0.01 μSv (thyroid scan with 1.85 MBq of administered I-iodide) to 0.4 μSv (brain scan with 26 MBq of Hg-chlormerodin). Occupational doses for the same diagnostic procedures starting in the mid-1960s but using Tc were also estimated. The doses estimated in this study show that the introduction of Tc resulted in an increase in occupational doses per procedure.
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Affiliation(s)
- Vladimir Drozdovitch
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Bethesda MD 20892
| | - Aaron B. Brill
- Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN 37232
| | - Fred A. Mettler
- Radiology and Nuclear Medicine Service, New Mexico VA Health Care System, 1501 San Pedro Blvd SE, Albuquerque, NM 87108
| | - William M. Beckner
- National Council on Radiation Protection and Measurements, Bethesda, MD
- Retired
| | - Stanley J. Goldsmith
- New York Presbyterian Hospital, Weill Cornell Medical Center, Starr 2-21, Nuclear Med Department, 525 East 68th St., New York, NY 10065
| | - Milton D. Gross
- Nuclear Medicine and Radiation Service, Department of Veterans Affairs Health System, 2215 Fuller Road, Ann Arbor, MI 48105
| | | | - Peter T. Kirchner
- National Institute of Biomedical Imaging and Biomedical Engineering, NIH, DHHS, 6707 Democracy Blvd, Bethesda, MD 20892
| | - James K. Langan
- Johns Hopkins University Medical Center, Baltimore, MD 21287
- Deceased
| | - Richard C. Reba
- Department of Radiology and Imaging Sciences, NIH Clinical Center, 10 Center Dr., Bethesda, MD 20892
| | - Gary T. Smith
- Departments of Nuclear Medicine, Tennessee Valley Healthcare System, Department of Veterans Affairs, 1310 24th Avenue South, Nashville, TN 37212
| | - André Bouville
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Bethesda MD 20892
- Retired
| | - Martha S. Linet
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Bethesda MD 20892
| | - Dunstana R. Melo
- Institute of Radiation Protection and Dosimetry, Av Salvador Allende S/N, Recreio dos Bandeirantes, Rio de Janeiro, RJ 22780-160 Brazil
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Bethesda MD 20892
| | - Steven L. Simon
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Bethesda MD 20892
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Chefer S, Reba RC, Leyson CZ, Seidel J, Johnson RF, Blaney JE, Jahrling PB, Dyall J. The effect of volume of interest definition on quantification of lymph node immune response to a monkeypox virus infection assessed by (18)F-FDG-PET. EJNMMI Res 2014; 4:49. [PMID: 26116113 PMCID: PMC4452685 DOI: 10.1186/s13550-014-0049-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 09/04/2014] [Indexed: 12/26/2022] Open
Abstract
Background 2-deoxy-2-[18F]fluoro-D-glucose-positron emission tomography (18F-FDG-PET) is applied in the clinic for infection assessment and is under consideration for investigating the inflammatory/immune response in lymphoid tissue in animal models of viral infection. Assessing changes in 18F-FDG uptake of lymph nodes (LNs), primary lymphoid tissues targeted during viral infection, requires suitable methods for image analysis. Similar to tumor evaluation, reliable quantitation of the LN function via multiple 18F-FDG-PET sessions will depend how the volume of interest is defined. Volume of interest definition has a direct effect on statistical outcome. The current study objective is to compare for the first time agreement between conventional and modified VOI metrics to determine which method(s) provide(s) reproducible standardized uptake values (SUVs) for 18F-FDG uptake in the LN of rhesus macaques. Methods Multiple 18F-FDG-PET images of LNs in macaques were acquired prior to and after monkeypox virus intravenous inoculation. We compared five image analysis approaches, SUVmax, SUVmean, SUVthreshold, modified SUVthreshold, and SUVfixed volume, to investigate the impact of these approaches on quantification of the changes in LN metabolic activity denoting the immune response during viral infection progression. Results The lowest data repeatability was observed with SUVmax. The best correspondence was between SUVfixed volume and conventional and modified SUVthreshold. A statistically significant difference in the LN 18F-FDG uptake between surviving and moribund animals was shown using modified SUVthreshold and SUVfixed volume (adjusted p = 0.0037 and p = 0.0001, respectively). Conclusions Quantification of the LN 18F-FDG uptake is highly sensitive to the method applied for PET image analysis. SUVfixed volume and modified SUVthreshold demonstrate better reproducibility for SUV estimates than SUVmax, SUVmean, and SUVthreshold. SUVfixed volume and modified SUVthreshold are capable of distinguishing between groups with different disease outcomes. Therefore, these methods are the preferred approaches for evaluating the LN function during viral infection by 18F-FDG-PET. Validation of multiple approaches is necessary to choose a suitable method to monitor changes in LN metabolic activity during progression of viral infection. Electronic supplementary material The online version of this article (doi:10.1186/s13550-014-0049-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Svetlana Chefer
- Division of Clinical Research, Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 8200 Research Plaza, Frederick, MD, 21702, USA,
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Eckelman WC, Jones AG, Duatti A, Reba RC. Progress using Tc-99m radiopharmaceuticals for measuring high capacity sites and low density sites. Drug Discov Today 2013; 18:984-91. [DOI: 10.1016/j.drudis.2013.06.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/14/2013] [Accepted: 06/17/2013] [Indexed: 01/11/2023]
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Dyall J, Johnson RF, Chen DY, Huzella L, Ragland DR, Mollura DJ, Byrum R, Reba RC, Jennings G, Jahrling PB, Blaney JE, Paragas J. Evaluation of monkeypox disease progression by molecular imaging. J Infect Dis 2011; 204:1902-11. [PMID: 22013221 PMCID: PMC3209815 DOI: 10.1093/infdis/jir663] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [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] [Received: 05/24/2011] [Accepted: 08/09/2011] [Indexed: 11/13/2022] Open
Abstract
Infection of nonhuman primates (NHPs) with monkeypox virus (MPXV) is currently being developed as an animal model of variola infection in humans. We used positron emission tomography and computed tomography (PET/CT) to identify inflammatory patterns as predictors for the outcome of MPXV disease in NHPs. Two NHPs were sublethally inoculated by the intravenous (IV) or intrabronchial (IB) routes and imaged sequentially using fluorine-18 fluorodeoxyglucose ((18)FDG) uptake as a nonspecific marker of inflammation/immune activation. Inflammation was observed in the lungs of IB-infected NHPs, and bilobular involvement was associated with morbidity. Lymphadenopathy and immune activation in the axillary lymph nodes were evident in IV- and IB-infected NHPs. Interestingly, the surviving NHPs had significant (18)FDG uptake in the axillary lymph nodes at the time of MPXV challenge with no clinical signs of illness, suggesting an association between preexisting immune activation and survival. Molecular imaging identified patterns of inflammation/immune activation that may allow risk assessment of monkeypox disease.
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Affiliation(s)
- Julie Dyall
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
| | - Reed F. Johnson
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases
| | - Dar-Yeong Chen
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
| | - Louis Huzella
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
| | - Dan R. Ragland
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
| | - Daniel J. Mollura
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Russell Byrum
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
| | - Richard C. Reba
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Gerald Jennings
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
| | - Peter B. Jahrling
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases
| | - Joseph E. Blaney
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases
| | - Jason Paragas
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases
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Poulose KP, Reba RC, Deland FH, Wagner HN. Role of liver scanning in the preoperative evaluation of patients with cancer. Br Med J 2011; 4:585-7. [PMID: 20791654 DOI: 10.1136/bmj.4.5683.585] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Liver scan characteristics and liver function tests of 72 patients with proved hepatic malignancy (54 metastatic, 18 primary) were evaluated. Well-defined focal defects were observed in 83% of patients with metastatic and 77% of patients with primary liver carcinoma. In 10% of the patients with metastatic liver disease the distribution of radioactivity was normal. Four or more biochemical liver function tests were normal in 33% of metastatic and 29% of primary liver cancer patients. Hepatic enlargement was present in the scan in 94% of the patients with liver metastases; however, data obtained from 104 necropsies of patients with hepatic metastases showed that only 46% had hepatomegaly. We recommend, therefore, that a liver scan should be performed before major tumour surgery in every patient with known malignancy regardless of normal liver size or normal liver function tests.
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Abstract
The purpose of this article is to summarize the role of gamma probes in intraoperative tumor detection in patients with colorectal cancer (CRC), as well as provide basic information about the physical and practical characteristics of the gamma probes, and the radiopharmaceuticals used in gamma probe tumor detection. In a significant portion of these studies, radiolabeled monoclonal antibodies (Mabs), particularly 125I labeled B72.3 Mab that binds to the TAG-72 antigen, have been used to target tumor. Studies have reported that intraoperative gamma probe radioimmunodetection helps surgeons to localize primary tumor, clearly delineate its resection margins and provide immediate intraoperative staging. Studies also have emphasized the value of intraoperative gamma probe radioimmunodetection in defining the extent of tumor recurrence and finding sub-clinical occult tumors which would assure the surgeons that they have completely removed the tumor burden. However, intraoperative gamma probe radioimmunodetection has not been widely adapted among surgeons because of some constraints associated with this technique. The main difficulty with this technique is the long period of waiting time between Mab injection and surgery. The technique is also laborious and costly. In recent years, Fluorine-18-2-fluoro-2-deoxy-D-glucose (18F-FDG) use in gamma probe tumor detection surgery has renewed interest among surgeons. Preliminary studies during surgery have demonstrated that use of FDG in gamma probe tumor detection during surgery is feasible and useful.
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Affiliation(s)
- Ismet Sarikaya
- Division of Nuclear Medicine, Georgetown University Hospital, Washington DC, 20007, USA.
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Eckelman WC, Reba RC, Kelloff GJ. Targeted imaging: an important biomarker for understanding disease progression in the era of personalized medicine. Drug Discov Today 2008; 13:748-59. [PMID: 18617011 DOI: 10.1016/j.drudis.2008.05.009] [Citation(s) in RCA: 39] [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] [Received: 03/18/2008] [Revised: 04/30/2008] [Accepted: 05/22/2008] [Indexed: 11/16/2022]
Abstract
The key to applying targeted imaging to personalized medicine is the choice of the right radiolabeled probe for the right target for the right disease following the lead of pharmaceutical development. The imaging approach differs depending on whether the target is a single disease control point (e.g. a specific receptor or transport protein linked to the mechanistic activity of a drug) or a general disease control point applicable to a number of treatment paradigms (e.g. proliferation, angiogenesis, inflammation). But in either case, the number of control points must be small given the time constraints on molecular imaging procedures in the clinic. Regardless of the choice, the radiotracer must be validated as binding to the target with the appropriate pharmacokinetics and pharmacodynamics for effective external imaging. Such an imaging agent developed in concert with drug development has a built in synergy that will accelerate the drug development process, targeted imaging and personalized medicine as well.
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Roeske JC, Lujan A, Reba RC, Penney BC, Diane Yamada S, Mundt AJ. Incorporation of SPECT bone marrow imaging into intensity modulated whole-pelvic radiation therapy treatment planning for gynecologic malignancies. Radiother Oncol 2005; 77:11-7. [PMID: 16024116 DOI: 10.1016/j.radonc.2005.06.017] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2003] [Revised: 06/03/2005] [Accepted: 06/05/2005] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND PURPOSE To incorporate single-photon emission computed tomography (SPECT) bone marrow (BM) imaging into the treatment planning process to reduce the volume of BM irradiated in gynecologic patients receiving intensity-modulated whole-pelvic radiation therapy (IM-WPRT). MATERIALS AND METHODS A planning CT scan was obtained of a patient with early stage endometrial cancer. The same patient also underwent a Tc-99m sulfur colloid SPECT scan of the pelvis. Tc-99m sulfur colloid is sequestered by the macrophages in the BM thereby identifying areas of active (red) BM. Using image fusion software, the SPECT scan was aligned with the planning CT scan and used to delineate regions of active BM. An IMRT plan was then generated to provide coverage of the planning target volume (PTV) while sparing areas of active BM and other normal pelvic structures. RESULTS The areas of high active BM density were observed predominantly in the lumbar vertebrae, sacrum and medial iliac crests. IMRT planning reduced the dose to these areas by 50% for doses greater than 30Gy compared to conventional planning. Furthermore, the IMRT plan did not compromise coverage of the PTV or sparing of normal tissues. CONCLUSIONS Our results suggest that SPECT-BM imaging is a useful adjunct to IMRT planning in gynecologic patients undergoing IM-WPRT.
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Affiliation(s)
- John C Roeske
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA .
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13
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Stinchcomb TG, Soyland C, Hassfjell SP, Westman J, Wang SJ, Whitlock JL, Reba RC, Rotmensch J, Roeske JC. Binary methods for the microdosimetric analysis of cell survival data from alpha-particle irradiation. Cancer Biother Radiopharm 2003; 18:481-7. [PMID: 12954136 DOI: 10.1089/108497803322285242] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A new type of alpha-particle irradiator allows survival of each cell to be observed individually along with the size and shape of its nucleus and the positions of the hits it receives. This paper discusses methods of data analysis that can utilize these additional data. Using idealizations of the cell nucleus geometry (i.e., spheres, ellipsoids), the path length (l), energy deposited (e), and specific energy (z) has been determined on a cell-by-cell basis for 772 cells all subjected to the same fluence. Each cell is regarded as a Bernoulli trial with a different probability for success (colony formation). For the survival expectation, A exp(-z/z(o)), the values of A and z(o) are chosen to maximize the likelihood for the observed outcome. Similar results are presented using the alternate functional forms A exp(-e/e(o)) and A exp(-l/l(o)). With these parameter values, the goodness of fit is also evaluated using a chi-square method with variances given by the binary (Bernoulli) methods. A further purpose of the paper is to assess the validity of the microdosimetric computations that would have had to be made if these individual cell-by-cell experimental measurements were not available or were incomplete.
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14
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Roeske JC, Soyland C, Wang SJ, Stinchcomb TG, Hassfjell SP, Whitlock JL, Reba RC, Rotmensch J. Image processing tools for alpha-particle track-etch dosimetry. Cancer Biother Radiopharm 2003; 18:425-30. [PMID: 12954129 DOI: 10.1089/108497803322285170] [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] [Indexed: 11/12/2022] Open
Abstract
In cases where both the source and cell geometry are well known, track-etch dosimetry allows the potential for individual cell dosimetry. However, analysis of track-etch images is both tedious and time-consuming. We describe here several image processing tools that we are using in conjunction with a track-etch based irradiator. Briefly, cells grown on LR 115 (a track-etch material) are irradiated from below by a collimated, planar alpha-particle source. Prior to irradiation, images of the cells are obtained. A computer program reads each image and automatically determines the location of individual cells. Next, the algorithm automatically identifies the cellular and nuclear boundaries. Following irradiation, and after the cells have reached their biological endpoint (e.g., cell survival), the cell dish is etched and images are obtained of alpha-particle tracks. Using the characteristic background pattern in the LR 115, the etched images are spatially registered to the original images. These two sets of images are then superimposed to create a composite image of the cells and associated alpha-particle tracks. Incorporating this tool into our irradiation scheme will enable more efficient analysis of the large amounts of data that are essential in assessing biological endpoints.
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Affiliation(s)
- John C Roeske
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL 60637, USA.
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15
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Wang SJ, Whitlock JL, Soyland C, Hassfjell SP, Stinchcomb TG, Rotmensch J, Reba RC, Roeske JC. Characterization of an alpha-particle irradiator for individual cell dosimetry measurements. Cancer Biother Radiopharm 2003; 18:437-44. [PMID: 12954131 DOI: 10.1089/108497803322285198] [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] [Indexed: 11/13/2022] Open
Abstract
A computer-controlled, alpha-particle irradiator is described that allows for the measurement of the number and location of alpha-particle hits to individual cell nuclei, and subsequent scoring of cell survival. Cells are grown on a track-etch material (LR 115) and images are obtained of the cells prior to irradiation. The cells are then irradiated from below by a planar, collimated Am-241 source. The exposure time is varied so that the average number of hits to cell nuclei ranges from 0 to 3. After cell survival has been scored, images of the etched material are obtained and spatially registered to the original cell images. The etched images and cellular images are superimposed allowing for the determination of the number and position of hits to individual cell nuclei. This paper characterizes the irradiator including the energy and fluence of the incident alpha particles. Additionally, we describe the sources of uncertainty associated with this experiment, including the cell dish repositioning and cell migration during scanning and irradiation.
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Affiliation(s)
- Steven J Wang
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA
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16
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Abstract
Despite advances in the understanding and treatment of ischemic cardiomyopathy, characterized by extensive coronary artery disease and left ventricular (LV) dysfunction, the prognosis remains poor with only a 50-60% 5-year survival rate. The composition of atherosclerotic lesions is currently regarded as being more important than the degree of stenosis in determining acute events. If imaging techniques could distinguish vulnerable from stable plaques, then high-risk patient subgroups could be identified. Another important concept is that LV dysfunction may be the result of either scarring due to necrosis or to the presence of myocardial hibernation, in which there is sufficient blood flow to sustain viable myocytes, but insufficient to maintain systolic contraction. This concept of myocardial viability is critical for making optimal clinical management decisions. This review describes how noninvasive imaging methods can be used to distinguish regions of irreversibly injured myocardium from viable but hibernating segments. Technical advances in CT and MR have made imaging of the beating heart possible. Considerable clinical progress has already been made and further cardiac applications are expected. Radiologists therefore have new opportunities for involvement in cardiac imaging but must recognize the political implications as well as the diagnostic potential of these modalities not only for the heart, but also for the whole vascular system. This review focuses on imaging myocardial injury. It compares state-of-the-art CT and MR with more established yet contemporary echocardiography and nuclear scintigraphy.
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Affiliation(s)
- Martin J Lipton
- Department of Radiology, University of Chicago, 5841 South Maryland, P220, MC 2026, Chicago, IL 60637, USA.
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17
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Reba RC. Comments about the contributions of Gopal Subramanian, PhD. Semin Nucl Med 2001. [DOI: 10.1053/snuc.2001.29378] [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: 11/11/2022]
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18
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Whitlock JL, Roeske JC, Dietz ML, Straus CM, Hines JJ, Horwitz EP, Reba RC, Rotmensch J. Radionuclide Therapy for the Treatment of Microscopic Ovarian Carcinoma: An Overview. Ind Eng Chem Res 2000. [DOI: 10.1021/ie000425u] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jenny L. Whitlock
- Departments of Obstetrics and Gynecology, Section of Oncology, of Radiation and Cellular Oncology, and Department of Radiology, The University of Chicago, Chicago, Illinois 60637, and Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - John C. Roeske
- Departments of Obstetrics and Gynecology, Section of Oncology, of Radiation and Cellular Oncology, and Department of Radiology, The University of Chicago, Chicago, Illinois 60637, and Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Mark L. Dietz
- Departments of Obstetrics and Gynecology, Section of Oncology, of Radiation and Cellular Oncology, and Department of Radiology, The University of Chicago, Chicago, Illinois 60637, and Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Chris M. Straus
- Departments of Obstetrics and Gynecology, Section of Oncology, of Radiation and Cellular Oncology, and Department of Radiology, The University of Chicago, Chicago, Illinois 60637, and Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - John J. Hines
- Departments of Obstetrics and Gynecology, Section of Oncology, of Radiation and Cellular Oncology, and Department of Radiology, The University of Chicago, Chicago, Illinois 60637, and Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - E. Philip Horwitz
- Departments of Obstetrics and Gynecology, Section of Oncology, of Radiation and Cellular Oncology, and Department of Radiology, The University of Chicago, Chicago, Illinois 60637, and Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Richard C. Reba
- Departments of Obstetrics and Gynecology, Section of Oncology, of Radiation and Cellular Oncology, and Department of Radiology, The University of Chicago, Chicago, Illinois 60637, and Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Jacob Rotmensch
- Departments of Obstetrics and Gynecology, Section of Oncology, of Radiation and Cellular Oncology, and Department of Radiology, The University of Chicago, Chicago, Illinois 60637, and Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
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Cohen VI, Jin B, McRee RC, Boulay SF, Cohen EI, Sood VK, Zeeberg BR, Reba RC. In vitro and in vivo m2 muscarinic subtype selectivity of some dibenzodiazepinones and pyridobenzodiazepinones. Brain Res 2000; 861:305-15. [PMID: 10760492 DOI: 10.1016/s0006-8993(00)02020-5] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Alzheimer's disease (AD) involves selective loss of muscarinic m2, but not m1, subtype receptors in cortical and hippocampal regions of the human brain. Emission tomographic study of the loss of m2 receptors in AD has been limited by the absence of available m2-selective radioligands, which can penetrate the blood-brain barrier. We now report on the in vitro and in vivo m2 muscarinic subtype selectivity of a series of dibenzodiazepinones and pyridobenzodiazepinones determined by competition studies against (R)-3-quinuclidinyl (S)-4-iodobenzilate ((R,S)-[125I]IQNB) or [3H]QNB. Of the compounds examined, three of the 5-[[4-[(4-dialkylamino)butyl]-1-piperidinyl]acetyl]-10, 11-dihydro-5-H-dibenzo[b,e][1,4]diazepin-11-ones (including DIBA) and three of the 11-[[4-[4-(dialkylamino)butyl]-1-phenyl]acetyl]-5, 11-dihydro-6H-pyrido [2,3-b][1,4]benzodiazepin-6-ones (including PBID) exhibited both high binding affinity for the m2 subtype (</=5 nM) and high m2/m1 selectivity (>/=10). In vivo rat brain dissection studies of the competition of PBID or DIBD against (R,S)[125I]IQNB or [3H]QNB exhibited a dose-dependent preferential decrease in the binding of the radiotracer in brain regions that are enriched in the m2 muscarinic subtype. In vivo rat brain autoradiographic studies of the competition of PBID, BIBN 99, or DIBD against (R,S)[125I]IQNB exhibited an insignificant effect of BIBN 99 and confirmed the effect of PBID and DIBD in decreasing the binding of (R,S)[125I]IQNB in brain regions that are enriched in the m2 muscarinic subtype. We conclude that PBID and DIBD are potentially useful parent compounds from which in vivo m2 selective derivatives may be prepared for potential use in positron emission tomographic (PET) study of the loss of m2 receptors in AD.
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Affiliation(s)
- V I Cohen
- Section of Radiopharmaceutical Chemistry, George Washington University Medical Center, Walter G. Ross Hall, 2300 Eye St., N.W., Washington, DC 20037, USA
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20
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Kim HJ, Zeeberg BR, Reba RC. Evaluation of reconstruction algorithms in SPECT neuroimaging. I. Comparison of statistical noise in SPECT neuroimages with 'naive' and 'realistic' predictions. Phys Med Biol 1999. [DOI: 10.1088/0031-9155/38/7/001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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21
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Affiliation(s)
- R Gunderman
- Department of Radiology, University of Chicago, IL 60637, USA
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22
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Cohen VI, Zeeberg BR, Boulay SF, Sood VK, Rayeq MR, Danesh RA, McPherson DW, Reba RC. In vivo competition studies of Z-(-,-)-[125I]IQNP against 3-quinuclidinyl 2-(5-bromothienyl)-2-thienylglycolate (BrQNT) demonstrating in vivo m2 muscarinic subtype selectivity for BrQNT. J Mol Neurosci 1998; 11:1-9. [PMID: 9826782 DOI: 10.1385/jmn:11:1:1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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] [Received: 08/19/1997] [Accepted: 12/15/1997] [Indexed: 11/11/2022]
Abstract
Alzheimer's disease (AD) involves selective loss of muscarinic m2, but not m1, subtype neuroreceptors in cortical and hippocampal regions of the human brain. Until recently, emission tomographic study of the loss of m2 receptors in AD has been limited by the absence of available m2-selective radioligands that can penetrate the blood-brain barrier. We now demonstrate the in vivo m2 selectivity of an analog of (R)-QNB, 3-quinuclidinyl 2-(5-bromothienyl)-2-thienylglycolate (BrQNT), by dissection and autoradiographic studies of the in vivo inhibition of radioiodinated Z-1-azabicyclo[2.2.2]oct-3-yl alpha-hydroxy-alpha-(1-iodo-1-propen-3-yl)-alpha-phenyl-acetate (Z-(-,-)-[125I]IQNP) binding by unlabeled BrQNT in rat brain. In the absence of BrQNT, Z-(-,-)-[125I]IQNP labels brain regions containing muscarinic receptors, with an enhanced selectivity for the m2 subtype. In the presence of 60-180 nmol of co-injected racemic BrQNT, Z-(-,-)-[125I]IQNP labeling in those brain regions containing predominantly m2 subtype is reduced to background levels, while levels of radioactivity in areas not enriched in the m2 subtype do not significantly decrease. We conclude that BrQNT is m2-selective in vivo, and that [76Br]BrQNT, or a radiofluorinated analog, may be of potential use in positron emission tomographic (PET) study of the loss of m2 receptors in AD. In addition, a radioiodinated analog may be of potential use in single photon emission tomographic (SPECT) studies.
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Affiliation(s)
- V I Cohen
- George Washington University Medical Center, Section of Radiopharmaceutical Chemistry, Washington, DC 20037, USA
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23
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Clouse JC, Rogers M, Reba RC, Littlefield JL, Schneider PB, Pollycove M. Nuclear medicine physician workforce requirements, Part 2: Benchmarking U.S. nuclear medicine physician workforce requirements based on managed care organization effects. Special Committee on Manpower. J Nucl Med 1998; 39:11N-13N, 27N, 30N. [PMID: 9669376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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24
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Cohen VI, Jin B, Cohen EI, Zeeberg BR, Reba RC. Synthesis of some substituted dibenzodiazepinones and pyridobenzodiazepinones. J Heterocycl Chem 1998. [DOI: 10.1002/jhet.5570350329] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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25
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Mundt AJ, Whitlock JL, Roeske JC, Hines JJ, Dietz ML, Reba RC, Harper PV, Rotmensch J. In vivo study of the alpha-emitting radionuclide bismuth-212 in the treatment of disseminated intraperitoneal ovarian carcinoma in an animal model. Int J Radiat Oncol Biol Phys 1998. [DOI: 10.1016/s0360-3016(98)80330-1] [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: 11/30/2022]
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26
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Rotmensch J, Whitlock JL, Schwartz JL, Hines JJ, Reba RC, Harper PV. In vitro and in vivo studies on the development of the alpha-emitting radionuclide bismuth 212 for intraperitoneal use against microscopic ovarian carcinoma. Am J Obstet Gynecol 1997; 176:833-40; discussion 840-1. [PMID: 9125608 DOI: 10.1016/s0002-9378(97)70608-2] [Citation(s) in RCA: 13] [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: 02/04/2023]
Abstract
OBJECTIVE Our objective was to develop the alpha-emitting radionuclide bismuth 212 for possible intraperitoneal use against microscopic ovarian cancer. STUDY DESIGN The radiobiologic effectiveness of bismuth 212 was compared in vitro to x rays and chromic phosphate phosphorus 32). The distribution, toxicity, and maximum tolerated dose of bismuth 212 were determined after intraperitoneal administration in animal models. Dose estimates in animals and humans were made. RESULTS In in vitro studies bismuth 212 was three times more effective in eradicating tumor cells grown in monolayers and in 800 microm spheroids. In in vivo studies bismuth 212 was distributed uniformly after intraperitoneal administration. The maximum tolerated dose in rabbits was 60 mCi. There was reversible hematologic toxicity with minimal organ damage. Bismuth 212 prolonged survival and cured up to 40% of animals inoculated with Ehrlich carcinoma cells. Dose estimates made from these studies indicated that dosages administered were effective in eradicating tumor cells and were within the radiotolerance of normal human tissue. CONCLUSION Bismuth 212 appears to be a suitable candidate for intraperitoneal use against microscopic ovarian cancer.
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Affiliation(s)
- J Rotmensch
- Department of Obstetrics and Gynecology, University of Chicago, IL 60637, USA
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27
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Zeeberg BR, Boulay SF, Gitler MS, Sood VK, Reba RC. Correction of the stereochemical assignment of the benzilic acid center in (R)-(-)-3-quinuclidinyl (S)-(+)-4-iodobenzilate [(R,S)-4-IQNB]. Appl Radiat Isot 1997; 48:463-7. [PMID: 9106987 DOI: 10.1016/s0969-8043(96)00290-4] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Radioiodinated (R)-quinuclidinyl-4-iodobenzilate (4IQNB) is a high affinity muscarinic antagonist which has been utilized for in vitro and in vivo assays, and for SPECT imaging in humans. 4IQNB exists in four different diastereomeric forms, since there are two asymmetric centers at the quinuclidinyl and benzilic acid centers. Based upon our in vivo studies, we have determined that the absolute stereochemistry previously assigned to the benzilic center was incorrect for the diastereomer that had been previously referred to as '(R)-quinuclidinyl-(R)-4-iodobenzilate' [(R,R)-4IQNB]. The correct designation for this diastereomer is '(R)-quinuclidinyl-(S)-4-iodobenzilate' [(R,S)-4IQNB].
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Affiliation(s)
- B R Zeeberg
- Department of Radiology, George Washington University Medical Center, Washington, DC 20037, USA
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28
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Kapp OH, Siemion J, Eckelman WC, Cohen VI, Reba RC. Molecular modeling of the interaction of diagnostic radiopharmaceuticals with receptor proteins: m2 antagonist binding to the muscarinic m2 subtype receptor. Recept Signal Transduct 1997; 7:177-201. [PMID: 9440504] [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: 05/22/2023]
Abstract
Models of the m2 muscarinic receptor have been built and acetylcholine and an antagonist of the quinuclidinyl benzilate family docked to the putative active site. We have incorporated aspects of homology, site-directed mutagenesis studies and structure-activity studies of specific lead compounds in the construction of our receptor models with a primary focus on the structure of the binding sites. We have observed a deep pocket binding of 5-BrQNT, suggesting a plausible explanation for the observation that agonists and antagonists do not bind competitively. The results of these computational studies are interpreted within the context of the observed in vitro results. Our goal is to assist in the development of subtype receptor selective radiopharmaceuticals for use in PET and SPECT.
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Affiliation(s)
- O H Kapp
- Department of Radiology, University of Chicago, IL 60637, USA
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29
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Sood VK, Lee KS, Boulay SF, Rayeq MR, McRee RC, Cohen EI, Zeeberg BR, He XS, Weinberger DR, Rice K, Reba RC. In vivo autoradiography of radioiodinated (R)-3-quinuclidinyl (S)-4-iodobenzilate [(R, S)-IQNB] and (R)-3-quinuclidinyl (R)-4-iodobenzilate [(R,R)-IQNB]. Comparison of the radiolabelled products of a novel tributylstannyl precursor with those of the established triazene and exchange methods. Appl Radiat Isot 1997; 48:27-35. [PMID: 9022211 DOI: 10.1016/s0969-8043(96)00125-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 02/03/2023]
Abstract
Radioiodinated (R,S)-IQNB and (R,R)-IQNB are prepared either from a triazene precursor or using an exchange reaction. In both cases the radiochemical yield is low. The product of the exchange reaction also suffers from having a fairly low specific activity. A new method for preparing radioiodinated (R,S)-IQNB and (R,R)-IQNB from a tributylstannyl precursor has recently been developed. This method is more convenient and much faster than the triazene and exchange methods, and it reliably results in a high radiochemical yield of a high specific activity product. In rat brain, the in vivo properties of the radioiodinated products of the tributylstannyl method are identical to those of the corresponding radioiodinated (R,S)-IQNB and (R,R)-IQNB prepared using the triazene and exchange methods. Dissection studies of selected brain regions show that at 3 h post injection (R,S)-[125I]IQNB prepared by all three methods have indistinguishable % dose g-1 values in all brain regions studied. Autoradiographic comparison of coronal slices through the anteroventral nucleus of the thalamus, through the hippocampus and through the pons at 2 h post injection shows that (R,S)-[125I]IQNB prepared by the triazene and tributylstannyl methods have indistinguishable patterns of binding.
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Affiliation(s)
- V K Sood
- Department of Radiology, George Washington University Medical Center, Washington, DC 20037, USA
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30
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Carretta RF, Cerqeira MD, Engelstad BL, Katzoff J, Lessig HJ, Lilien DL, Littlefield JL, Neagley FL, Peterson RE, Pollycove M, Reba RC, Schneider PB, Shah AN, Weislo WJ, Wegst A. Future nuclear medicine physician requirements. J Nucl Med 1996; 37:15N-19N. [PMID: 8965131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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31
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Boulay SF, McRee RC, Cohen VI, Sood VK, Zeeberg BR, Reba RC. Specific binding component of the "inactive" stereoisomer (S,S)-[125I] IQNB to rat brain muscarinic receptors in vivo. Nucl Med Biol 1996; 23:211-9. [PMID: 8782228 DOI: 10.1016/0969-8051(95)02047-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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: 02/02/2023]
Abstract
In vivo nonspecific binding can be estimated using the inactive stereoisomer of a receptor radioligand. However, the binding of the inactive stereoisomer may be partially specific. Specific binding of the inactive (S,S)-[125I]IQNB was estimated from the inhibition induced by a competing nonradioactive ligand. This technique differed from the usual approach, since it was used to study the inactive rather than the active stereoisomer. The results indicate that there is substantial specific binding for (S,S)-[125I]IQNB.
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Affiliation(s)
- S F Boulay
- Department of Radiology, George Washington University Medical Center, Washington DC 20037, USA
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32
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Luo H, Hasan A, Sood V, McRee RC, Zeeberg B, Reba RC, McPherson DW, Knapp FF. Evaluation of 1-azabicyclo[2.2.2]oct-3-yl alpha-fluoroalkyl-alpha-hydroxy-alpha-phenylacetates as potential ligands for the study of muscarinic receptor density by positron emission tomography. Nucl Med Biol 1996; 23:267-76. [PMID: 8782236 DOI: 10.1016/0969-8051(95)02066-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 02/02/2023]
Abstract
Both 1-azabicyclo[2.2.2]oct-3-yl alpha-(1-fluoroeth-2-yl)-alpha-hydroxy-alpha-phenylacetate (FQNE, 5) and 1-azabicyclo[2.2.2]oct-3-yl alpha-(1-fluoropent-5-yl)-alpha-hydroxy-alpha-phenylacetate (FQNPe, 6) were prepared and evaluated as potential candidates for the determination of muscarinic cholinergic receptor (mAChR) density by positron emission tomography (PET). The results of in vitro binding assays demonstrated that although both 5 and 6 had high binding affinities for m1 and m2 mAChR subtypes, 6 displayed a higher affinity (nM, m1; KD, 0.45, m2; KD, 3.53) as compared to 5 (nM, m1; KD, 12.5, m2; KD, 62.8). It was observed that pretreatment of female Fisher rats with either 5 or 6 prior to the i.v. administration of Z-(-)(-)-[131I]-IQNP, a high-affinity muscarinic ligand, significantly blocked the uptake of radioactivity in the brain and heart measured 3 h postinjection of the radiolabeled ligand. These new fluoro QNB analogues represent important target ligands for evaluation as potential receptor imaging agents in conjunction with PET.
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Affiliation(s)
- H Luo
- Health Sciences Research Division, Oak Ridge National Laboratory (Ornl), TN 37831-6229, USA
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33
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Williams KA, Lang RM, Reba RC, Taillon LA. Comparison of technetium-99m sestamibi-gated tomographic perfusion imaging with echocardiography and electrocardiography for determination of left ventricular mass. Am J Cardiol 1996; 77:750-5. [PMID: 8651128 DOI: 10.1016/s0002-9149(97)89211-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Left ventricular (LV) mass estimates obtained from post-stress gated single-photon emission computed tomographic (SPECT) perfusion images were compared with 2-dimensionally targeted M-mode echocardiograms and with resting electrocardiographic voltage in 32 patients with stress perfusion scans that were either normal or only mildly abnormal. Myocardial pixel volumes were obtained from SPECT transaxial slices at end-diastole, end-systole, and summed ("ungated") static reformatted SPECT images at 2 levels of background subtraction, 37.5% and 35% of peak myocardial activity. The S-wave amplitude in lead V1 and the R-wave amplitude in V5 were summed for an electrocardiographic index of voltage. Echocardiographic LV mass was calculated using the modified Penn convention formula. SPECT myocardial mass estimates were significantly greater at diastole when compared with systolic or summed images. There was a moderated, although highly significant, correlation between echocardiographic and SPECT indexes of LV mass with the lower (35%) background threshold (r = 0.59, 0.60, and 0.53 for diastole, summed, and systole, each p < 0.001). The diastolic SPECT estimate of LV mass correlation with electrocardiographic voltage (r = 0.56) was superior to the correlation between echocardiography and electrocardiography (r = 0.30). With use of published criteria for the presence of LV hypertrophy on echocardiography, diastolic and systolic gated SPECT predicted echocardiographic results with 78% accuracy.
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Affiliation(s)
- K A Williams
- Department of Medicine (Cardiology), The University of Chicago, Illinois, USA
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Boulay SF, Sood VK, Rayeq MR, Cohen VI, Zeeberg BR, Reba RC. Autoradiographic evidence that 3-quinuclidinyl-4-fluorobenzilate (FQNB) displays in vivo selectivity for the m2 subtype. Neuroimage 1996; 3:35-9. [PMID: 9345473 DOI: 10.1006/nimg.1996.0004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 02/05/2023] Open
Abstract
Alzheimer's disease (AD) involves selective loss of muscarinic m2, but not m1, subtype neuroreceptors in cortical and hippocampal regions of the human brain. Emission tomographic study of the loss of m2 receptors in AD is limited by the fact that there is currently no available m2-selective radioligand which can penetrate the blood-brain barrier. We now demonstrate the in vivo m2 selectivity of a fluorine derivative of QNB (FQNB), by studying autoradiographically the in vivo inhibition of radioiodinated (R)-3-quinuclidinyl (S)-4-iodobenzilate ((R,S)-[125I]IQNB) binding by unlabeled FQNB. In the absence of FQNB, (R,S)-[125I]IQNB labels brain regions in proportion to the total muscarinic receptor concentration; in the presence of 30.0 nmol of racemic FQNB, (R,S)-[125I]IQNB labeling in those brain regions containing predominantly the m2 subtype is reduced to background levels. We conclude that FQNB is m2-selective in vivo and that [18F]FQNB or a closely related analogue may be of potential use in positron emission tomographic study of the loss of m2 receptors in AD.
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Affiliation(s)
- S F Boulay
- Section of Radiopharmaceutical Chemistry, Walter G. Ross Hall, George Washington University Medical Center, Washington, DC 20037, USA
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35
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McPherson DW, Lambert CR, Jahn K, Sood V, McRee RC, Zeeberg B, Reba RC, Knapp FF. Resolution and in vitro and initial in vivo evaluation of isomers of iodine-125-labeled 1-azabicyclo[2.2.2]oct-3-yl alpha-hydroxy-alpha-(1-iodo-1-propen-3-yl)-alpha-phenylacetate: a high-affinity ligand for the muscarinic receptor. J Med Chem 1995; 38:3908-17. [PMID: 7562924 DOI: 10.1021/jm00020a004] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [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
1-Azabicyclo[2.2.2]oct-3-yl alpha-hydroxy-alpha-(1-iodo-1-propen-3-yl)- alpha-phenylacetate (IQNP, 1), is a highly selective ligand for the muscarinic acetylcholinergic receptor (mAChR). There are eight stereoisomers in the racemic mixture. The optical isomers of alpha-hydroxy-alpha-phenyl-alpha-(1-propyn-3-yl)acetic acid were resolved as the alpha-methylbenzylamine salts, and the optical isomers of 3-quinuclidinol were resolved as the tartrate salts. The E and Z isomers were prepared by varying the reaction conditions for the stannylation of the triple bond followed by purification utilizing flash column chromatography. In vitro binding assay of the four stereoisomers containing the (R)-(-)-3-quinuclidinyl ester demonstrated that each isomer of 1 bound to mAChR with high affinity. In addition, (E)-(-)-(-)-IQNP demonstrated the highest receptor subtype specificity between the m1 molecular subtype (KD, nM, 0.383 +/- 0.102) and the m2 molecular subtype (29.6 +/- 9.70). In vivo biodistribution studies demonstrated that iodine-125-labeled (E)-(-)-(+)-1 cleared rapidly from the brain and heart. In contrast, iodine-125-labeled (E)-(-)-(-)-, (Z)-(-)-(-)-, and (Z)-(-)-(+)-1 have high uptake and retention in mAChR rich areas of the brain. It was also observed that (E)-(-)-(-)-IQNP demonstrated an apparent subtype selectivity in vivo with retention in M1 (m1, m4) mAChR areas of the rain. In addition, (Z)-(-)-(-)-IQNP also demonstrated significant uptake in tissues containing the M2 (m2) mAChR subtype. These results demonstrate that the iodine-123-labeled analogues of the (E)-(-)-(-)- and (Z)-(-)-(-)-IQNP isomers are attractive candidates for single-photon emission-computed tomographic imaging of cerebral and cardiac mAChR receptor densities.
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Affiliation(s)
- D W McPherson
- Health Sciences Research Division, Oak Ridge National Laboratory (ORNL), Tennessee 37831-6229, USA
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Boulay SF, Sood VK, Rayeq MR, McRee RC, Cohen EI, Cohen VI, Zeeberg BR, Reba RC. Autoradiographic evidence that quinuclidinyl 4-(bromophenyl)-2-thienylglycolate (QBPTG) displays in vivo selectivity for the muscarinic m2 subtype. Neuroimage 1995; 2:209-13. [PMID: 9343604 DOI: 10.1006/nimg.1995.1027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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: 02/05/2023] Open
Abstract
Alzheimer's disease (AD) involves selective loss of muscarinic m2, but not m1, subtype neuroreceptors in cortical and hippocampal regions of the human brain. Emission tomographic study of the loss of m2 receptors in AD is limited by the fact that there is currently no available m2-selective radioligand which can penetrate the blood-brain barrier. We now demonstrate the in vivo m2 selectivity of an analogue of QNB, 4-(bromophenyl)-2-thienylglycolate (QBPTG), by studying autoradiographically the in vivo inhibition of radioiodinated (R)-3-quinuclidinyl (S)-4-iodobenzilate ((R,S)-[125I]IQNB) binding by unlabeled QBPTG in rat brain. In the absence of QBPTG, (R,S)-[125I]IQNB labels brain regions in proportion to the total muscarinic receptor concentration; in the presence of 37.5 nmol of racemic QBPTG, (R,S)-[125I]IQNB labeling in those brain regions containing predominantly the m2 subtype is reduced to background levels. We conclude that QBPTG is m2-selective in vivo and that [76Br]QBPTG, or a radiofluorinated analogue, may be of potential use in positron emission tomographic study of the loss of m2 receptors in AD. In addition, a radioiodinated analogue may be of potential use in single photon emission tomographic studies.
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Affiliation(s)
- S F Boulay
- George Washington University Medical Center, Section of Radiopharmaceutical Chemistry, Washington, DC 20037, USA
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Katzenellenbogen JA, Coleman RE, Hawkins RA, Krohn KA, Larson SM, Mendelsohn J, Osborne CK, Piwnica-Worms D, Reba RC, Siegel BA. Tumor receptor imaging: proceedings of the National Cancer Institute workshop, review of current work, and prospective for further investigations. Clin Cancer Res 1995; 1:921-32. [PMID: 9816063] [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: 02/09/2023]
Abstract
In February 1994, the National Cancer Institute held a workshop to evaluate the current and future role of emission tomographic imaging methods, positron emission tomography and single-photon emission computed tomography, in improving the accuracy of cancer diagnosis and the effectiveness of treatment and in elucidating basic aspects of human cancer biology. Reviews covered many of the receptor and transport systems for hormones and growth factors, as well as metabolic changes important in human cancer, and topical presentations reviewed the current status of receptor-based imaging in the most well-characterized systems: somatostatin receptor imaging of neuroendocrine tumors, estrogen receptor imaging of breast cancer, and epidermal growth factor receptor and tumor metabolic imaging. A critical analysis was made of the current research and of new directions for the future development and use of receptor-imaging methods in oncology. In each area, recommendations were made for further investigation, where emerging understanding of tumor cell biology and defined molecular targets might be combined with the methods of radiopharmaceutical design and evaluation, to develop new approaches to critical issues in the diagnosis, staging, and treatment of cancer through tumor receptor imaging.
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Gitler MS, Boulay SF, Sood VK, McPherson DW, Knap FF, Zeeberg BR, Reba RC. Characterization of in vivo brain muscarinic acetylcholine receptor subtype selectivity by competition studies against (R,S)-[125I]IQNB. Brain Res 1995; 687:71-8. [PMID: 7583315 DOI: 10.1016/0006-8993(95)00458-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [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
We have studied the in vivo rat brain muscarinic acetylcholine receptor (mAChR) m2 subtype selectivities of three quinuclidine derivatives: (R)-3-quinuclidinyl benzilate (QNB), E-(+,+)-1-azabicyclo[2.2.2]oct-3-yl alpha-hydroxy-alpha-(1-iodo-1-propen-3-yl)-alpha-phenylacetate (E-(+,+)-IQNP), and E-(+,-)-1-azabicyclo[2.2.2]oct-3-yl alpha-hydroxy-alpha-(1-iodo-1-propen-3-yl)-alpha-phenylacetate (E-(+,-)-IQNP), and two tricyclic ring compounds: 5-[[4-[4-(diisobutylamino)butyl]-1-phenyl]-10,11-dihydro-5H-dibenz o [b,e][1,4]diazepin-11-one [sequence: see text] (DIBD) and 11-[[4-[4-(diisobutylamino)butyl-1-phenyl]acetyl]-5,11-dihydro-6H- pyrido [2,3-b][1,4]benzodiazepin-6-one [sequence: see text] (PBID), by correlating the regional inhibition of (R,S)-[125I]IQNB with the regional composition of the m1-m4 subtypes. Subtle effects are demonstrated after reduction of the between-animal variability by normalization to corpus striatum. Substantial in vivo m2-selectivity is exhibited by QNB and DIBD, modest in vivo m2-selectivity is exhibited by E-(+,+)-IQNP, and little or no in vivo m2-selectivity is exhibited by PBID and E-(+,-)-IQNP. Surprisingly, the in vivo m2-selectivity is not correlated with the in vitro m2-selectivity. For example, QNB, which appears to be the most strongly in vivo m2-selective compound, exhibits negligible in vitro m2-selectivity. These examples indicate that a strategy which includes only preliminary in vitro screening may very well preclude the discovery of a novel compound which would prove useful in vivo.
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Affiliation(s)
- M S Gitler
- Department of Radiology, George Washington University Medical Center, Washington, DC 20037, USA
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McRee RC, Boulay SF, Sood VK, Cohen EI, Cohen VI, Gitler MS, Zeeberg BR, Gibson RE, Reba RC. Autoradiographic evidence that QNB displays in vivo selectivity for the m2 subtype. Neuroimage 1995; 2:55-62. [PMID: 9343590 DOI: 10.1006/nimg.1995.1008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [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: 02/05/2023] Open
Abstract
Alzheimer's disease (AD) involves selective loss of muscarinic m2, but not m1, subtype neuroreceptors in cortical and hippocampal regions of the human brain. Emission tomographic study of the loss of m2 receptors in AD is limited by the fact that there is currently no available m2-selective radioligand which can penetrate the blood-brain barrier. We have previously reported the results of in vivo dissection studies, using both carrier-free and low specific activity [3H]QNB, which show that [3H]QNB exhibits a substantial in vivo m2 selectivity. Because of the expense of the radioligand and the long exposure time required for the X-ray film, performing a large number of direct in vivo autoradiographic studies using [3H]QNB is precluded. Therefore, we now confirm these results autoradiographically by studying the in vivo inhibition of radio-iodinated (R)-3-quinuclidinyl (S)-4-iodobenzilate ((R,S)-[125I]IQNB) binding by unlabeled QNB. In the absence of QNB, (R,S)-[125I]IQNB labels brain regions in proportion to the total muscarinic receptor concentration; in the presence of 15 nmol QNB, (R,S,)-[125I]IQNB labeling in those brain regions containing predominantly m2 subtype is reduced to background levels. We conclude that QNB is m2-selective in vivo and that a suitably radiolabeled derivative of QNB, possibly labeled with 18F, may be of potential use in positron emission tomographic study of the loss of m2 receptors in AD.
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Affiliation(s)
- R C McRee
- George Washington University Medical Center, Section of Radiopharmaceutical Chemistry, Washington, DC 20037, USA
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Cohen VI, Jin B, Gitler MS, de la Cruz RA, Boulay SF, Sood VK, Zeeberg BR, Reba RC. Novel potent and m2-selective antimuscarinic compounds which penetrate the blood-brain barrier. Eur J Med Chem 1995. [DOI: 10.1016/0223-5234(96)88210-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Cohen VI, Jin B, Gitler MS, De Cruz RAL, Rzeszotarski WJ, Zeeberg BR, Baumgold J, Reba RC. Synthesis of some dibenzodiazepinone derivatives as potent and m2-selective antimuscarinic compounds. J Heterocycl Chem 1994. [DOI: 10.1002/jhet.5570310416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Hiramatsu Y, Kawai R, Reba RC, Blasberg RG, Baum BJ. Kinetic analysis of rat exocrine gland muscarinic receptors in vivo. J Pharmacol Exp Ther 1994; 269:1205-12. [PMID: 8014864] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Recently we employed two enantiomers of the muscarinic antagonist quinuclidinyl iodobenzilate (IQNB), and pharmacokinetic analyses, to define and quantitate nonspecific and specific binding to rat parotid gland muscarinic acetylcholine receptors (mAChRs) in vivo (Hiramatsu et al., 1993). The present studies were designed to utilize this same approach for evaluating mAChRs in three other morphologically different rat exocrine glands: the submandibular, sublingual and lacrimal glands. The metabolism and tissue distribution of the intravenously injected IQNB enantiomers were determined, and the resulting data were assessed in terms of their goodness of fit to several multicompartmental models. All three exocrine glands showed substantial nonspecific ligand distribution as measured with the receptor-inert enantiomer (SS)-IQNB. Nonspecific distribution represented 45, 21 and 36% of total ligand distribution in submandibular, sublingual and lacrimal glands, respectively, as measured with the receptor-active enantiomer (RR)-IQNB. The rank order of the binding potential, kinetically equivalent to Bmax/Kd, for (RR)-IQNB and these mAChRs was lacrimal > sublingual > submandibular glands (674 +/- 235 > 575 +/- 109 > 345 +/- 29). These results demonstrate that specific mAChRs in the exocrine glands can be measured in vivo with the (RR)-IQNB enantiomer and that despite some small quantitative differences, the distribution of (RR)- and (SS)-IQNB is similar in the three exocrine glands but is substantially different from that in brain and heart.
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Affiliation(s)
- Y Hiramatsu
- Clinical Investigations and Patient Care Branch National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland
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Reba RC. Lines from the president. J Nucl Med 1994; 35:24N-26N. [PMID: 8113881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Abstract
Muscarinic M2 receptors have been found to be severely depleted in post-mortem brains of Alzheimer's patients. This loss of receptor may represent a useful diagnostic marker, if it could be quantitatively imaged with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging. In order to develop a radioligand with selectivity for muscarinic M2 receptors, we now report that 3-alpha-chlorimperialine is a potent M2 receptor antagonist with a Ki of 0.32 nM at M2 receptors, a 12-fold selectivity for M2 over M1 receptors, and a 5-fold selectivity for M2 over M4 receptors. Furthermore, 2% of the injected dose of 3-alpha-chlorimperialine per gram tissue penetrates into brain within 30 min, then washes out gradually. Taken together, these studies demonstrate that 3-alpha-chlorimperialine is a potent M2-selective muscarinic antagonist that penetrates into brain and may be a useful substrate for radioiodination and subsequent imaging of brain muscarinic M2 receptors.
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Affiliation(s)
- J Baumgold
- Department of Radiology, George Washington University Medical Center, Washington, DC 20037
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Abstract
We have determined the binding of (R)-3-Quinuclidinyl 8-xanthenecarboxylate to muscarinic acetylcholine receptor preparations from rat cortex, hippocampus, caudate/putamen, thalamus, pons and colliculate bodies. The competition curves determined with [3H]quinuclidinyl benzilate as the radioligand are well described by a two site model with a difference in affinity between the two sites of 12-fold. The proportions of high affinity site vary from 100% in the caudate/putamen to 0% in the pons/medulla. The selectivities are different from those measured by pirenzepine and are consistent with QNX exhibiting similar affinity for the M1, M3, and M4 receptors with lower affinity for the M2 receptor. This assignment was confirmed by determining the affinities of QNX for the cloned receptor subtypes.
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Affiliation(s)
- R E Gibson
- Department of Radiology, George Washington University Medical Center, Washington, D.C. 20037
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Abstract
Alzheimer's disease (AD) involves selective loss of muscarinic m2, but not m1, subtype neuroreceptors in the posterior parietal cortex of the human brain. Emission tomographic study of the loss of m2 receptors in AD is limited by the fact that there is currently no available m2-selective radioligand which can penetrate the blood-brain barrier. [3H](R)-3-quinuclidinylbenzilate ([3H]QNB) is commonly used for performing in vitro studies of the muscarinic acetylcholine receptor (mAChR), either with membrane homogenates or with autoradiographic slices, in which [3H]QNB is nonsubtype-selective. We report here the results of in vivo studies, using both carrier-free and low specific activity [3H]QNB, which show that [3H]QNB exhibits a substantial in vivo m2-selectivity. Previously reported in vivo (R)-3-quinuclidinyl (R)-4-iodobenzilate ((R,R)-[125I]IQNB) binding appears to be nonsubtype-selective. Apparently the bulky iodine substitution in the 4 position reduces the subtype selectivity of QNB. It is possible that a less bulky fluorine substitution might permit retention of the selectivity exhibited by QNB itself. We conclude that a suitably radiolabeled derivative of QNB, possibly labeled with 18F, may be of potential use in positron emission tomographic (PET) study of the loss of m2 receptors in AD.
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Affiliation(s)
- M S Gitler
- Department of Radiology, George Washington University Medical Center, Washington, D.C
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John CS, Bowen WD, Saga T, Kinuya S, Vilner BJ, Baumgold J, Paik CH, Reba RC, Neumann RD, Varma VM. A malignant melanoma imaging agent: synthesis, characterization, in vitro binding and biodistribution of iodine-125-(2-piperidinylaminoethyl)4-iodobenzamide. J Nucl Med 1993; 34:2169-75. [PMID: 8254405] [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: 01/29/2023] Open
Abstract
In order to develop improved radiopharmaceuticals for imaging malignant melanoma, we have synthesized and characterized 125I-and 131I-labeled (2-piperidinylaminoethyl)4-iodobenzamide (PAB). In vitro binding profiles of IPAB and N-(2-diethylaminoethyl)4-iodobenzamide (IDAB, a structurally related analog of IPAB) for a variety of neurotransmitter receptors suggested that both IPAB and IDAB possessed a high sigma-1 affinity and a low affinity for sigma-2 sites. In vitro homologous competition binding studies of [125I]PAB with human malignant melanoma cell A2058 showed that the tracer was bound to the cells with a high affinity (Ki = 6.0 nM) and that the binding was saturable. Biodistribution studies in nude mice implanted with human malignant melanoma xenografts showed good tumor uptake (3.87% ID/g at 1 hr, 2.91% ID/g at 6 hr and 1.02% ID/g at 24 hr) of [125I]PAB. High tumor-to-nontarget organ ratios were obtained at 24 hr postinjection. Tumor-to-blood, liver, muscle, lung, intestines, heart and brain ratios at 24 hr were 17.80, 3.88, 94.58, 14.29, 10.87, 37.07 and 90.01, respectively. Tumor imaging with [131I]PAB in a nude mice model xenografted with human malignant melanoma at 24 hr clearly delineated the tumor with very little activity in any other organ. These results demonstrate that sigma-1 receptors could be used as external markers for malignant melanoma.
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Affiliation(s)
- C S John
- George Washington University Medical Center, Washington, DC
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48
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Reba RC. PET and SPECT: opportunities and challenges for psychiatry. J Clin Psychiatry 1993; 54 Suppl:26-32. [PMID: 8270595] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are the most advanced technologies available for the functional imaging of the brain, surpassing magnetic resonance imaging (MRI) and computed tomography (CT) scanners in potential clinical and research applications in neuropsychiatry. PET deals with a small number of radionuclides with short physical half-lives and an exclusive energy of 511 keV; SPECT utilizes an ensemble of radionuclides that exhibit moderate physical half-lives, each with its own characteristic spectrum of energy. PET imaging instrumentation requires substantial refinements to enable utilization with high-energy photons, larger data sets, and a high magnitude of information flow per unit of time. The instrumentation enables greater sensitivity and resolution, as compared with SPECT, but requires a more extensive data acquisition and processing infrastructure, resulting in a significantly higher system cost. SPECT has a number of price/performance alternatives in configuring a system, and has further cost advantages in that it utilizes widely available chemical tracers.
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Affiliation(s)
- R C Reba
- Department of Radiology, University of Chicago, Pritzker School of Medicine, Ill. 60637-1470
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Affiliation(s)
- R C Reba
- University of Chicago (III) Pritzker School of Medicine
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50
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