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Bray M, Di Mascio M, de Kok-Mercado F, Mollura DJ, Jagoda E. Radiolabeled antiviral drugs and antibodies as virus-specific imaging probes. Antiviral Res 2010; 88:129-142. [PMID: 20709111 PMCID: PMC7125728 DOI: 10.1016/j.antiviral.2010.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Accepted: 08/09/2010] [Indexed: 12/04/2022]
Abstract
A number of small-molecule drugs inhibit viral replication by binding directly to virion structural proteins or to the active site of a viral enzyme, or are chemically modified by a viral enzyme before inhibiting a downstream process. Similarly, antibodies used to prevent or treat viral infections attach to epitopes on virions or on viral proteins expressed on the surface of infected cells. Such drugs and antibodies can therefore be thought of as probes for the detection of viral infections, suggesting that they might be used as radiolabeled tracers to visualize sites of viral replication by single-photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging. A current example of this approach is the PET imaging of herpes simplex virus infections, in which the viral thymidine kinase phosphorylates radiolabeled thymidine analogues, trapping them within infected cells. One of many possible future applications might be the use of a radiolabeled hepatitis C protease inhibitor to image infection in animals or humans and provide a quantitative measure of viral burden. This article reviews the basic features of radionuclide imaging and the characteristics of ideal tracer molecules, and discusses how antiviral drugs and antibodies could be evaluated for their suitability as virus-specific imaging probes. The use of labeled drugs as low-dose tracers would provide an alternative application for compounds that have failed to advance to clinical use because of insufficient in vivo potency, an unsuitable pharmacokinetic profile or hepato- or nephrotoxicity.
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Affiliation(s)
- Mike Bray
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702, United States
| | - Michele Di Mascio
- Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, United States
| | - Fabian de Kok-Mercado
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702, United States
| | - Daniel J Mollura
- Center for Infectious Disease Imaging, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD 20892, United States
| | - Elaine Jagoda
- Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States
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2
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Massoud TF. In Vivo Molecular Imaging in Oncology. Cancer Imaging 2008. [DOI: 10.1016/b978-012374212-4.50095-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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3
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Hughes JA, Hartman NG, Jay M. Preparation of [11C]-thymidine and [11C]-2′-arabino-2′-fluoro-β-5-methyl-uridine (FMAU) using a hollow fiber membrane bioreactor system. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580361204] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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4
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Affiliation(s)
- Jun Toyohara
- Research Center, Research and Development Division, Nihon Medi-Physics, Co., Ltd., Chiba, Japan
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Jacobs AH, Winkeler A, Dittmar C, Hilker R, Heiss WD. Prospects of molecular imaging in neurology. J Cell Biochem 2003; 39:98-109. [PMID: 12552609 DOI: 10.1002/jcb.10414] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Molecular imaging aims towards the non-invasive kinetic and quantitative assessment and localization of biological processes of normal and diseased cells in vivo in animal models and humans. Due to technological advances during the past years, imaging of molecular processes is a rapidly growing field, which has the potential of broad applications in the study of cell biology, biochemistry, gene/protein function and regulation, signal transduction, characterization of transgenic animals, development of new treatment strategies (gene or cell-based) and their successful implementation into clinical application. Most importantly, the possibility to study these parameters in the same subject repeatedly over time makes molecular imaging an attractive technology to obtain reliable data and to safe recourse; for example, molecular imaging enables the assessment of an exogenously introduced therapeutic gene and the related alterations of endogenously regulated gene functions directly in the same subject. Therefore, molecular imaging will have great implications especially when molecular diagnostic and treatment modalities have to be translated from experimental into clinical application. Here, we review the three main imaging technologies, which have been developed for studying molecular processes in vivo, the disease models, which have been studied so far, and the potential future applications.
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Affiliation(s)
- A H Jacobs
- Max Planck-Institute for Neurological Research, Center of Molecular Medicine (ZMMK), Cologne, Germany.
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6
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Avril N, Bengel FM. Defining the success of cardiac gene therapy: how can nuclear imaging contribute? Eur J Nucl Med Mol Imaging 2003; 30:757-71. [PMID: 12541135 DOI: 10.1007/s00259-002-1100-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Gene therapy is a promising modality for the treatment of various cardiovascular diseases such as ischaemia, heart failure, restenosis after revascularisation, hypertension and hyperlipidaemia. An increasing number of approaches are moving from experimental and preclinical validation to clinical application, and several multi-centre trials are currently underway. Despite the rapid progress in cardiac gene therapy, many basic tools and principles remain under development. Questions with regard to the optimal method for gene delivery in a given situation remain open, as do questions concerning therapeutic efficacy and the time course and magnitude of gene expression in target and remote areas. Nuclear imaging provides valuable tools to address these open issues non-invasively. Functional effects of molecular therapy at the tissue level can be identified using tracers of blood flow, metabolism, innervation or cell death. The use of reporter genes and radiolabelled reporter probes allows for non-invasive assessment of location, magnitude and persistence of transgene expression in the heart and the whole body. Co-expression of a reporter gene will allow for indirect imaging of the expression of a therapeutic gene of choice, and linkage of measures of transgene expression to downstream functional effects will enhance the understanding of basic mechanisms of cardiac gene therapy. Hence, nuclear imaging offers great potential to facilitate and refine the determination of therapeutic effects in preclinical and clinical cardiovascular gene therapy.
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Affiliation(s)
- Norbert Avril
- Division of Nuclear Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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Doubrovin M, Ponomarev V, Serganova I, Soghomonian S, Myagawa T, Beresten T, Ageyeva L, Sadelain M, Koutcher J, Blasberg RG, Tjuvajev JGG. Development of a new reporter gene system--dsRed/xanthine phosphoribosyltransferase-xanthine for molecular imaging of processes behind the intact blood-brain barrier. Mol Imaging 2003; 2:93-112. [PMID: 12964307 DOI: 10.1162/15353500200303130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
We report the development of a novel dual-modality fusion reporter gene system consisting of Escherichia coli xanthine phosphoribosyltransferase (XPRT) for nuclear imaging with radiolabeled xanthine and Discosoma red fluorescent protein for optical fluorescent imaging applications. The dsRed/XPRT fusion gene was successfully created and stably transduced into RG2 glioma cells, and both reporters were shown to be functional. The level of dsRed fluorescence directly correlated with XPRT enzymatic activity as measured by ribophosphorylation of [14C]-xanthine was in vitro (Ki = 0.124 +/- 0.008 vs. 0.00031 +/- 0.00005 mL/min/g in parental cell line), and [*]-xanthine octanol/water partition coefficient was 0.20 at pH = 7.4 (logP = -0.69), meeting requirements for the blood-brain barrier (BBB) penetrating tracer. In the in vivo experiment, the concentration of [14C]-xanthine in the normal brain varied from 0.20 to 0.16 + 0.05% dose/g under 0.87 + 0.24% dose/g plasma radiotracer concentration. The accumulation in vivo in the transfected flank tumor was to 2.4 +/- 0.3% dose/g, compared to 0.78 +/- 0.02% dose/g and 0.64 +/- 0.05% dose/g in the control flank tumors and intact muscle, respectively. [14C]-Xanthine appeared to be capable of specific accumulation in the transfected infiltrative brain tumor (RG2-dsRed/XPRT), which corresponded to the 585 nm fluorescent signal obtained from the adjacent cryosections. The images of endogenous gene expression with the "sensory system" have to be normalized for the transfection efficiency based on the "beacon system" image data. Such an approach requires two different "reporter genes" and two different "reporter substrates." Therefore, the novel dsRed/XPRT fusion gene can be used as a multimodality reporter system in the biological applications requiring two independent reporter genes, including the cells located behind the BBB.
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Affiliation(s)
- Mikhail Doubrovin
- Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, Box 513, New York, NY 10021, USA
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8
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Sharma V, Luker GD, Piwnica-Worms D. Molecular imaging of gene expression and protein function in vivo with PET and SPECT. J Magn Reson Imaging 2002; 16:336-51. [PMID: 12353250 DOI: 10.1002/jmri.10182] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Molecular imaging is broadly defined as the characterization and measurement of biological processes in living animals, model systems, and humans at the cellular and molecular level using remote imaging detectors. One underlying premise of molecular imaging is that this emerging field is not defined by the imaging technologies that underpin acquisition of the final image per se, but rather is driven by the underlying biological questions. In practice, the choice of imaging modality and probe is usually reduced to choosing between high spatial resolution and high sensitivity to address a given biological system. Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) inherently use image-enhancing agents (radiopharmaceuticals) that are synthesized at sufficiently high specific activity to enable use of tracer concentrations of the compound (picomolar to nanomolar) for detecting molecular signals while providing the desired levels of image contrast. The tracer technologies strategically provide high sensitivity for imaging small-capacity molecular systems in vivo (receptors, enzymes, transporters) at a cost of lower spatial resolution than other technologies. We review several significant PET and SPECT advances in imaging receptors (somatostatin receptor subtypes, neurotensin receptor subtypes, alpha(v)beta(3) integrin), enzymes (hexokinase, thymidine kinase), transporters (MDR1 P-glycoprotein, sodium-iodide symporter), and permeation peptides (human immunodeficiency virus type 1 (HIV-1) Tat conjugates), as well as innovative reporter gene constructs (herpes simplex virus 1 thymidine kinase, somatostatin receptor subtype 2, cytosine deaminase) for imaging gene promoter activation and repression, signal transduction pathways, and protein-protein interactions in vivo.
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Affiliation(s)
- Vijay Sharma
- Molecular Imaging Center, Mallinckrodt Institute of Radiology and Department of Molecular Biology and Pharmacology, Washington University Medical School, St. Louis, Missouri 63110, USA
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9
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Jacobs AH, Dittmar C, Winkeler A, Garlip G, Heiss WD. Molecular Imaging of Gliomas. Mol Imaging 2002; 1:309-35. [PMID: 12926228 DOI: 10.1162/15353500200221392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Gliomas are the most common types of brain tumors. Although sophisticated regimens of conventional therapies are being carried out to treat patients with gliomas, the disease invariably leads to death over months or years. Before new and potentially more effective treatment strategies, such as gene- and cell-based therapies, can be effectively implemented in the clinical application, certain prerequisites have to be established. First of all, the exact localization, extent, and metabolic activity of the glioma must be determined to identify the biologically active target tissue for a biological treatment regimen; this is usually performed by imaging the expression of up-regulated endogenous genes coding for glucose or amino acid transporters and cellular hexokinase and thymidine kinase genes, respectively. Second, neuronal function and functional changes within the surrounding brain tissue have to be assessed in order to save this tissue from therapy-induced damage. Third, pathognomonic genetic changes leading to disease have to be explored on the molecular level to serve as specific targets for patient-tailored therapies. Last, a concerted noninvasive analysis of both endogenous and exogenous gene expression in animal models as well as the clinical setting is desirable to effectively translate new treatment strategies from experimental into clinical application. All of these issues can be addressed by multimodal radionuclide and magnetic resonance imaging techniques and fall into the exciting and fast growing field of molecular and functional imaging. Noninvasive imaging of endogenous gene expression by means of positron emission tomography (PET) may reveal insight into the molecular basis of pathogenesis and metabolic activity of the glioma and the extent of treatment response. When exogenous genes are introduced to serve for a therapeutic function, PET imaging may reveal the assessment of the “location,” “magnitude,” and “duration” of therapeutic gene expression and its relation to the therapeutic effect. Detailed reviews on molecular imaging have been published from the perspective of radionuclide imaging (Gambhir et al., 2000; Blasberg and Tjuvajev, 2002) as well as magnetic resonance and optical imaging (Weissleder, 2002). The present review focuses on molecular imaging of gliomas with special reference on the status and perspectives of imaging of endogenous and exogenously introduced gene expression in order to develop improved diagnostics and more effective treatment strategies of gliomas and, in that, to eventually improve the grim prognosis of this devastating disease.
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Affiliation(s)
- A H Jacobs
- Max-Planck-Institute for Neurological Research, University of Cologne, Germany.
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10
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Jacobs AH, Winkler A, Dittmar C, Gossman A, Deckert M, Kracht L, Thiel A, Garlip G, Hilker R, Sobesky J, Vollmar S, Kummer C, Graf R, Voges J, Wienhard K, Herholz K, Heiss WD. Molecular and functional imaging technology for the development of efficient treatment strategies for gliomas. Technol Cancer Res Treat 2002; 1:187-204. [PMID: 12622512 DOI: 10.1177/153303460200100304] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Gliomas are the most common types of brain tumors, which invariably lead to death over months or years. Before new and potentially more effective treatment strategies, such as gene therapy, can be effectively introduced into clinical application the following goals must be reached: (1) the determination of localization, extent and metabolic activity of the glioma; (2) the assessment of functional changes within the surrounding brain tissue; (3) the identification of genetic changes on the molecular level leading to disease; and in addition (4) a detailed non-invasive analysis of both endogenous and exogenous gene expression in animal models and in the clinical setting. Non-invasive imaging of endogenous gene expression by means of positron emission tomography (PET) may reveal insight into the molecular basis of pathogenesis and metabolic activity of the glioma and the extent of treatment response. When exogenous genes are introduced to serve for a therapeutic function, PET imaging techniques may reveal the assessment of the location, magnitude and duration of therapeutic gene expression and its relation to the therapeutic effect. Here, we review the main principles of PET imaging and its key roles in neurooncology research.
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Affiliation(s)
- A H Jacobs
- Max Planck-Institute for Neurological Research, Center of Molecular Medicine (ZMMK), University of Cologne, Cologne, Germany.
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11
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Affiliation(s)
- G D Luker
- Laboratory of Molecular Radiopharmacology, Molecular Imaging Center, Mallinckrodt Institute of Radiology, Washington University Medical School, St Louis, MO 63110, USA
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12
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Gambhir SS, Herschman HR, Cherry SR, Barrio JR, Satyamurthy N, Toyokuni T, Phelps ME, Larson SM, Balatoni J, Finn R, Sadelain M, Tjuvajev J, Blasberg R. Imaging transgene expression with radionuclide imaging technologies. Neoplasia 2000; 2:118-38. [PMID: 10933072 PMCID: PMC1550287 DOI: 10.1038/sj.neo.7900083] [Citation(s) in RCA: 273] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A variety of imaging technologies are being investigated as tools for studying gene expression in living subjects. Noninvasive, repetitive and quantitative imaging of gene expression will help both to facilitate human gene therapy trials and to allow for the study of animal models of molecular and cellular therapy. Radionuclide approaches using single photon emission computed tomography (SPECT) and positron emission tomography (PET) are the most mature of the current imaging technologies and offer many advantages for imaging gene expression compared to optical and magnetic resonance imaging (MRI)-based approaches. These advantages include relatively high sensitivity, full quantitative capability (for PET), and the ability to extend small animal assays directly into clinical human applications. We describe a PET scanner (microPET) designed specifically for studies of small animals. We review "marker/reporter gene" imaging approaches using the herpes simplex type 1 virus thymidine kinase (HSV1-tk) and the dopamine type 2 receptor (D2R) genes. We describe and contrast several radiolabeled probes that can be used with the HSV1-tk reporter gene both for SPECT and for PET imaging. We also describe the advantages/disadvantages of each of the assays developed and discuss future animal and human applications.
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Affiliation(s)
- S S Gambhir
- Department of Molecular and Medical Pharmacology, UCLA School of Medicine, Los angeles, CA 90095-1770, USA.
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Gambhir SS, Barrio JR, Herschman HR, Phelps ME. Assays for noninvasive imaging of reporter gene expression. Nucl Med Biol 1999; 26:481-90. [PMID: 10473186 DOI: 10.1016/s0969-8051(99)00021-9] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Repeated, noninvasive imaging of reporter gene expression is emerging as a valuable tool for monitoring the expression of genes in animals and humans. Monitoring of organ/cell transplantation in living animals and humans, and the assessment of environmental, behavioral, and pharmacologic modulation of gene expression in transgenic animals should soon be possible. The earliest clinical application is likely to be monitoring human gene therapy in tumors transduced with the herpes simplex virus type 1 thymidine kinase (HSV1-tk) suicide gene. Several candidate assays for imaging reporter gene expression have been studied, utilizing cytosine deaminase (CD), HSV1-tk, and dopamine 2 receptor (D2R) as reporter genes. For the HSV1-tk reporter gene, both uracil nucleoside derivatives (e.g., 5-iodo-2'-fluoro-2'-deoxy-1-beta-D-arabinofuranosyl-5-iodouracil [FIAU] labeled with 124I, 131I) and acycloguanosine derivatives [e.g., 8-[18F]fluoro-9-[[2-hydroxy-1-(hydroxymethyl)ethoxy]methyl]guanine (8-[18F]-fluoroganciclovir) ([18F]FGCV), 9-[(3-[18F]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([18F]FHPG)] have been investigated as reporter probes. For the D2R reporter gene, a derivative of spiperone [3-(2'-[18F]-Fluoroethyl)spiperone ([18F]FESP)] has been used with positron emission tomography (PET) imaging. In this review, the principles and specific assays for imaging reporter gene expression are presented and discussed. Specific examples utilizing adenoviral-mediated delivery of a reporter gene as well as tumors expressing reporter genes are discussed.
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Affiliation(s)
- S S Gambhir
- The Crump Institute for Biological Imaging, Department of Molecular and Medical Pharmacology, UCLA School of Medicine, Los Angeles, California 90095-1770, USA.
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Tamada K, Fujinaga S, Watanabe R, Yamashita R, Takeuchi Y, Osano M. Specific deposition of passively transferred monoclonal antibodies against herpes simplex virus type 1 in rat brain infected with the virus. Microbiol Immunol 1995; 39:861-71. [PMID: 8657013 DOI: 10.1111/j.1348-0421.1995.tb03283.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The kinetics of human monoclonal antibody (anti-gB) to herpes simplex virus type 1 (HSV-1) were investigated after intravenous injection of anti-gB into an HSV-1 encephalitis animal model. Immunohistochemical study revealed specific deposition of passively transferred anti-gB in the hippocampus and thalamus of the infected rat brain, and it bound to the same neurons in which HSV-1 antigen was positively stained. To examine the macroscopic distribution of anti-gB in the infected brain, we undertook an 125I-labeled anti-gB injection study, and the same distribution of 125I-labeled anti-gB deposition was observed by brain semimicroautoradiography as in the immunohistochemical study. These results suggest that anti-gB easily permeates the capillary wall and is deposited in the inflammatory site where HSV-1-specific antigen is detectable. The use of radioisotope-labeled anti-gB injection and external brain imaging could lead to a noninvasive diagnostic tool for the early detection of HSV-1 antigen in cases of suspected HSV-1 encephalitis.
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Affiliation(s)
- K Tamada
- Division of Pediatrics, Tachikawa Kyosai Hospital, Tokyo, Japan
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15
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Conti PS, Alauddin MM, Fissekis JR, Schmall B, Watanabe KA. Synthesis of 2'-fluoro-5-[11C]-methyl-1-beta-D-arabinofuranosyluracil ([11C]-FMAU): a potential nucleoside analog for in vivo study of cellular proliferation with PET. Nucl Med Biol 1995; 22:783-9. [PMID: 8535339 DOI: 10.1016/0969-8051(95)00017-r] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Rapid in vivo catabolism limits the use of currently available radiotracers used in tumor proliferation studies with PET. This is manifested by the need to develop complex mathematical models to interpret kinetic and metabolite data obtained from imaging studies with agents such as carbon-11 labeled thymidine. A potential carbon-11 labeled radiotracer for cellular proliferation, 2'-fluoro-5-([11C]-methyl)-1-beta-D-arabinofuranosyluracil (FMAU), has been prepared using a previously described method for preparation of [11C]methyl-thymidine where selective alkylation of a pyrimidyl dianion is accomplished with [11C]methyl iodide at the 5-position of the pyrimidine ring. FMAU shares many in vivo characteristics of thymidine, including cellular transport, phosphorylation by mammalian kinase, and incorporation into DNA. Most importantly, in vivo catabolism of FMAU is limited, potentially yielding simplified kinetic models for determination of cellular proliferation with positron emission tomography.
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Affiliation(s)
- P S Conti
- PET Imaging Science Center, University of Southern California, School of Medicine, Los Angeles, CA 90033, USA
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Affiliation(s)
- T Tsuchiya
- Institute of Bioorganic Chemistry, Kawasaki, Japan
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Margolis TP, LaVail JH, Setzer PY, Dawson CR. Selective spread of herpes simplex virus in the central nervous system after ocular inoculation. J Virol 1989; 63:4756-61. [PMID: 2552151 PMCID: PMC251112 DOI: 10.1128/jvi.63.11.4756-4761.1989] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The spread of herpes simplex virus (HSV) was studied in the mouse central nervous system (CNS) after ocular inoculation. Sites of active viral replication in the CNS were identified by autoradiographic localization of neuronal uptake of tritiated thymidine. Labeled neurons were first noted in the CNS at 4 days postinoculation in the Edinger-Westphal nucleus, ipsilateral spinal trigeminal nucleus, pars caudalis, pars interpolaris, and ipsilateral dorsal horn of the rostral cervical spinal cord. By 5 days postinoculation, additional sites of labeling included the seventh nerve nucleus, nucleus locus coeruleus, and the nuclei raphe magnus and raphe pallidus. None of these sites are contiguous to nuclei infected at 4 days, but all are synaptically related to these nuclei. By 7 days postinoculation, no new foci of labeled cells were noted in the brain stem, but labeled neurons were noted in the amygdala, hippocampus, and somatosensory cortex. Neurons in both the amygdala and hippocampus receive axonal projections from the locus coeruleus. On the basis of these findings, we conclude that the spread of HSV in the CNS after intracameral inoculation is not diffuse but is restricted to a small number of noncontiguous foci in the brain stem and cortex which become infected in a sequential fashion. Since these regions are synaptically related, the principal route of the spread of HSV in the CNS after ocular infection appears to be along axons, presumably via axonal transport rather than by local spread.
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Affiliation(s)
- T P Margolis
- F. I. Proctor Foundation, San Francisco, California
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18
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Abstract
Herpes simplex encephalitis (HSE) is an uncommon disease, yet 25 to 30 per cent of cases involve children. The initial clinical findings are nonspecific (fever, altered mental status), but most cases evolve to demonstrate focal neurologic signs and symptoms. The CSF is abnormal in over 90 per cent of cases. The EEG, CT, and MRI will further help in detecting focal encephalitis. The clinician caring for a child with focal encephalitis should institute broad-spectrum antimicrobial therapy plus acyclovir, pending definitive diagnosis by ancillary tests or brain biopsy, which is positive for HSE 33 to 55 per cent of the time and is diagnostic for other treatable conditions 10 to 20 per cent of the time. Acyclovir is the drug of choice for HSE and substantially reduces mortality and morbidity. The management of HSE in a child requires an experienced team of specialists and laboratory support in a tertiary intensive care setting.
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Affiliation(s)
- S Kohl
- Department of Pediatrics, University of Texas Medical School, Houston
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19
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Rand KH, Raad I, el Koussi A, Houck HJ, Brey W, Rocca J, Loftsson T, Bodor N. Trifluorothymidine: potential non-invasive diagnosis of herpes simplex infection using 19F nuclear magnetic resonance in a murine hepatitis model. J Virol Methods 1987; 18:257-69. [PMID: 2832432 PMCID: PMC7119731 DOI: 10.1016/0166-0934(87)90087-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Trifluorothymidine (TFT) is known to be concentrated in herpes simplex virus (HSV) infected cells in vitro in the form of phosphorylated derivatives. We studied a murine hepatitis model of HSV infection to determine whether this in vitro observation would also be demonstrable in vivo. Following i.v. injection of 100 or 160 mg/kg TFT, TFT was found in significantly higher concentrations in the livers of HSV-2 infected mice than in the livers of uninfected mice, mice infected with murine hepatitis virus (MHV-A59) or mice with hepatitis from carbon tetrachloride treatment. Neither altered renal function, nor altered pharmacokinetics could account for this difference. 19F Nuclear Magnetic Resonance spectroscopy readily detected the 19F from TFT in both liver extracts and whole livers, particularly at higher tissue levels, i.e. greater than 50 micrograms/g tissue. If further studies with living animals support these preliminary observations, clinical application could be pursued.
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Affiliation(s)
- K H Rand
- Department of Pathology, Gainesville Veterans Administration Medical Center, Florida
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Cleator GM, Klapper PE, Sharma H, Longson M. A rat model of herpes encephalitis with special reference to its potential for the development of diagnostic brain imaging. J Neurol Sci 1987; 79:55-66. [PMID: 3039067 DOI: 10.1016/0022-510x(87)90259-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A rat model of herpes encephalitis using intraocular inoculation of herpes simplex virus strain SC16 was investigated. Virus distribution in the brain was examined by virus isolation and immunocytochemical staining using immuno-gold silver and peroxidase-anti-peroxidase. At 5 days post-infection virus was found in the thalamus, hypothalamus, septum, colliculus, geniculate bodies, the pons, trapezoidium and medulla oblongata, but less frequently, in the cerebellum and occipital lobes. Possible routes of spread of virus and the potential of this model in neuro-radiological scanning procedures are discussed.
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De Clercq E, Walker RT. Chemotherapeutic agents for herpesvirus infections. PROGRESS IN MEDICINAL CHEMISTRY 1986; 23:187-218. [PMID: 2821580 DOI: 10.1016/s0079-6468(08)70343-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Perlman ME, Conti PS, Schmall B, Watanabe KA. Synthesis and purification of the anti-viral agent 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodocytosine (FIAC) labeled with iodine-125. INTERNATIONAL JOURNAL OF NUCLEAR MEDICINE AND BIOLOGY 1984; 11:215-8. [PMID: 6530342 DOI: 10.1016/0047-0740(84)90002-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The 125I labeled analog of 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodocytosine (FIAC) has been prepared for studies on the imaging of herpes simplex virus (HSV) encephalitis infections in animals. Iodination of 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)cytosine X HCl (FAC X HCl) with Na 125I and NaI/HIO3 in aqueous acetic acid, and subsequent removal of residual iodine by CCl4 extraction and ion exchange chromatography, yielded [125I]FIAC in aqueous solution with a specific activity of 45.5 mCi/mmol in 44% radiochemical yield, and with a radiopurity of 96-97%. Methods for further purification are described.
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