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Kepp KP, Robakis NK, Høilund-Carlsen PF, Sensi SL, Vissel B. The amyloid cascade hypothesis: an updated critical review. Brain 2023; 146:3969-3990. [PMID: 37183523 DOI: 10.1093/brain/awad159] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 04/20/2023] [Accepted: 04/23/2023] [Indexed: 05/16/2023] Open
Abstract
Results from recent clinical trials of antibodies that target amyloid-β (Aβ) for Alzheimer's disease have created excitement and have been heralded as corroboration of the amyloid cascade hypothesis. However, while Aβ may contribute to disease, genetic, clinical, imaging and biochemical data suggest a more complex aetiology. Here we review the history and weaknesses of the amyloid cascade hypothesis in view of the new evidence obtained from clinical trials of anti-amyloid antibodies. These trials indicate that the treatments have either no or uncertain clinical effect on cognition. Despite the importance of amyloid in the definition of Alzheimer's disease, we argue that the data point to Aβ playing a minor aetiological role. We also discuss data suggesting that the concerted activity of many pathogenic factors contribute to Alzheimer's disease and propose that evolving multi-factor disease models will better underpin the search for more effective strategies to treat the disease.
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Affiliation(s)
- Kasper P Kepp
- Section of Biophysical and Biomedicinal chemistry, DTU Chemistry, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Nikolaos K Robakis
- Icahn School of Medicine at Mount Sinai Medical Center, New York, NY 10029, USA
| | - Poul F Høilund-Carlsen
- Department of Nuclear Medicine, Odense University Hospital, 5000 Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, 5000 Odense C, Denmark
| | - Stefano L Sensi
- Center for Advanced Studies and Technology-CAST, and Institute for Advanced Biotechnology (ITAB), University G. d'Annunzio of Chieti-Pescara, Chieti, 66013, Italy
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, 66013, Italy
| | - Bryce Vissel
- St Vincent's Hospital Centre for Applied Medical Research, St Vincent's Hospital, Sydney, 2010, Australia
- School of Clinical Medicine, UNSW Medicine and Health, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, Sydney, NSW 2052, Australia
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2
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Li L, Xiang F, Yao L, Zhang C, Jia X, Chen A, Liu Y. Synthesis and evaluation of curcumin-based near-infrared fluorescent probes for detection of amyloid β peptide in Alzheimer mouse models. Bioorg Med Chem 2023; 92:117410. [PMID: 37506558 DOI: 10.1016/j.bmc.2023.117410] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/04/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023]
Abstract
The abnormal accumulation of amyloid β protein (Aβ) is one of the most important causes of Alzheimer's disease (AD) and is usually a detecting biomarker. Curcumin and its derivatives have potential Aβ aggregate targeting ability; we synthesized a series of curcumin-based near-infrared fluorescence probes in this study. By characterizing the excitation wavelength and emission wavelength, the imaging characteristics of the investigation in the near-infrared light region were determined; with an increase in the concentration of the probe compounds, the fluorescence intensity showed an upward trend, demonstrating ideal optical characteristics. In vivo, imaging results showed that the synthesized probe compounds could penetrate the blood-brain barrier (BBB) and specifically bind to Aβ in the brain of APP/PS1 mice. Especially for compound 3b, the maximum emission wavelength was around 667 nm, and the fluorescence signal intensity in the brain of the APP/PS1 mice model was more than twice that of the wild control group at 120 min after administration, which could display Aβ pathological changes. The fluorescent probes designed in this study can become an effective tool for early AD diagnosis and visual detection.
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Affiliation(s)
- Li Li
- School of Pharmacy, Liaoning University, Shenyang 110036, People's Republic of China; Liaoning Key Laboratory of New Drug Research & Development, Shenyang 110036, People's Republic of China
| | - Fengting Xiang
- School of Pharmacy, Liaoning University, Shenyang 110036, People's Republic of China
| | - Luyang Yao
- School of Pharmacy, Liaoning University, Shenyang 110036, People's Republic of China
| | - Chuang Zhang
- School of Pharmacy, Liaoning University, Shenyang 110036, People's Republic of China
| | - Xirong Jia
- School of Pharmacy, Liaoning University, Shenyang 110036, People's Republic of China
| | - Anqi Chen
- School of Pharmacy, Liaoning University, Shenyang 110036, People's Republic of China
| | - Yu Liu
- School of Pharmacy, Liaoning University, Shenyang 110036, People's Republic of China; Liaoning University, Judicial Expertise Center, Shenyang 110036, People's Republic of China.
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3
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Kepp KP, Sensi SL, Johnsen KB, Barrio JR, Høilund-Carlsen PF, Neve RL, Alavi A, Herrup K, Perry G, Robakis NK, Vissel B, Espay AJ. The Anti-Amyloid Monoclonal Antibody Lecanemab: 16 Cautionary Notes. J Alzheimers Dis 2023; 94:497-507. [PMID: 37334596 DOI: 10.3233/jad-230099] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
After the CLARITY-AD clinical trial results of lecanemab were interpreted as positive, and supporting the amyloid hypothesis, the drug received accelerated Food and Drug Administration approval. However, we argue that benefits of lecanemab treatment are uncertain and may yield net harm for some patients, and that the data do not support the amyloid hypothesis. We note potential biases from inclusion, unblinding, dropouts, and other issues. Given substantial adverse effects and subgroup heterogeneity, we conclude that lecanemab's efficacy is not clinically meaningful, consistent with numerous analyses suggesting that amyloid-β and its derivatives are not the main causative agents of Alzheimer's disease dementia.
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Affiliation(s)
- Kasper P Kepp
- Department of Chemistry, Section of Biophysical and Biomedicinal Chemistry, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Stefano L Sensi
- Center for Advanced Studies and Technology - CAST, and Institute for Advanced Biotechnology (ITAB), University G. d'Annunzio of Chieti-Pescara, Italy
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Italy
| | - Kasper B Johnsen
- Department of Health Science and Technology, Neurobiology Research and Drug Delivery Group, Aalborg University, Aalborg, Denmark
| | - Jorge R Barrio
- Department of Molecular and Medical Pharmacology, UCLA School of Medicine, Los Angeles, CA, USA
| | - Poul F Høilund-Carlsen
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Rachael L Neve
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Abass Alavi
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA USA
| | - Karl Herrup
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - George Perry
- Department of Neuroscience, Developmental and Regenerative Biology, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Nikolaos K Robakis
- Icahn School of Medicine at Mount Sinai Medical Center, New York, NY, USA
| | - Bryce Vissel
- St Vincent's Hospital Centre for Applied Medical Research, St Vincent's Hospital, Darlinghurst, NSW, Australia
- School of Clinical Medicine, UNSW Medicine & Health, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW, Australia
| | - Alberto J Espay
- Department of Neurology, James J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, University of Cincinnati, Cincinnati, OH, USA
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4
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Newberg AB, Coble R, Khosravi M, Alavi A. Positron Emission Tomography-Based Assessment of Cognitive Impairment and Dementias, Critical Role of Fluorodeoxyglucose in such Settings. PET Clin 2022; 17:479-494. [PMID: 35717103 DOI: 10.1016/j.cpet.2022.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Positron emission tomography (PET) has been a key component in the diagnostic armamentarium for assessing neurodegenerative diseases such as Alzheimer or Parkinson disease. PET imaging has been useful for diagnosing these disorders, identifying their pathophysiology, and following their treatment. Further, PET imaging has been extensively used for both clinical and research purposes, particularly for helping with potential therapeutic approaches for managing neurodegenerative diseases. This article will review the current literature regarding PET imaging in patients with neurodegenerative disorders. This includes an evaluation of the most commonly used tracer fluorodeoxyglucose that measures cerebral glucose metabolism, tracers that assess neurotransmitter systems, and tracers designed to reveal disease-specific pathophysiological processes. With the continuing development of an expanding variety of radiopharmaceuticals, PET imaging will likely play a prominent role in future research and clinical applications for neurodegenerative diseases.
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Affiliation(s)
- Andrew B Newberg
- Marcus Institute of Integrative Health, Thomas Jefferson University, 789 East Lancaster Avenue, Suite 110, Villanova, PA 19085, USA; Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA.
| | - Roger Coble
- Marcus Institute of Integrative Health, Thomas Jefferson University, 789 East Lancaster Avenue, Suite 110, Villanova, PA 19085, USA; University of California Berkeley, Berkeley, CA, USA
| | - Mohsen Khosravi
- Marcus Institute of Integrative Health, Thomas Jefferson University, 789 East Lancaster Avenue, Suite 110, Villanova, PA 19085, USA
| | - Abass Alavi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
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5
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Høilund-Carlsen PF, Alavi A. Aducanumab (Marketed as Aduhelm) Approval Is Likely Based on Misinterpretation of PET Imaging Data. J Alzheimers Dis 2021; 84:1457-1460. [PMID: 34657891 DOI: 10.3233/jad-215275] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
According to the FDA, aducanumab (Aduhelm), the recently approved anti-Alzheimer drug, reduces the level of cerebral amyloid plaques-a hallmark finding in patients with Alzheimer's disease-and this will result in a reduction in clinical decline. The authors of this article are not convinced that amyloid deposits are a hallmark of Alzheimer's disease and are of the opinion that the apparent reduction in amyloid accumulation following aducanumab treatment is likely instead a result of continued and advanced cerebral cell death and, thus, not a sign of improvement but of an even more advanced disease.
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Affiliation(s)
- Poul F Høilund-Carlsen
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark.,Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Abass Alavi
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
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Wimo A, Belger M, Bon J, Jessen F, Dumas A, Kramberger MG, Jamilis L, Johansson G, Rodrigo Salas A, Rodríguez Gómez O, Sannemann L, Stoekenbroek M, Gurruchaga Telleria M, Valero S, Vermunt L, Waterink L, Winblad B, Visser PJ, Zwan M, Boada M. A Cost-Consequence Analysis of Different Screening Procedures in Alzheimer's Disease: Results from the MOPEAD Project. J Alzheimers Dis 2021; 83:1149-1159. [PMID: 34420954 PMCID: PMC8543247 DOI: 10.3233/jad-210303] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Background: For care planning and support, under-detection and late diagnosis of Alzheimer’s disease (AD) is a great challenge. Models of Patient-Engagement for Alzheimer’s Disease (MOPEAD) is an EU-funded project aiming at testing different strategies to improve this situation. Objective: To make a cost-consequence analysis of MOPEAD. Methods: Four screening strategies were tested in five countries (Germany, the Netherlands, Slovenia, Spain, and Sweden): 1) a web-approach; 2) Open-House initiative; 3) in primary care; and 4) by diabetes specialists. Persons-at-risk of AD in all strategies were offered referral to a hospital-based specialist. The primary health-economic outcome was the cost per true-positive case (TP) of AD from the screened population. Results: Of 2,847 screened persons, 1,121 screened positive (39%), 402 were evaluated at memory clinics (14%), and 236 got an AD diagnosis (8%). The cost per TP of those screened was €3,115 with the web-approach, €2,722 with the Open-House, €1,530 in primary care, and €1,190 by diabetes specialists. Sensitivity analyses that more likely reflect the real-world situation confirmed the results. The number-needed-to-screen was 30 with the web-approach, 8 with the Open-House and primary care, and 6 with the diabetes specialists. There were country differences in terms of screening rates, referrals to memory clinics, staff-types involved, and costs per TP. Conclusion: In primary care and by the diabetes specialist, the costs per TP/screened population were lowest, but the capacity of such settings to identify cases with AD-risk must be discussed. Hence new diagnostic strategies such as web-solutions and Open-House initiatives may be valuable after modifications.
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Affiliation(s)
- Anders Wimo
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, Solna, Sweden
| | - Mark Belger
- Eli Lilly and Company Ltd (ELI), Bracknell, UK
| | - Jaka Bon
- University Medical Centre Ljubljana (UMCL), Ljubljana, Slovenia
| | - Frank Jessen
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Psychiatry, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) Universität zu Köln, Köln, Germany.,Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Germany
| | - Annette Dumas
- ASDM Consulting, EU Affairs Director, Brussels, Belgium
| | - Milica G Kramberger
- Department of Neurology, University Medical Center Ljubljana and Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Laura Jamilis
- GMV Soluciones Globales Internet S.A.U. (GMV), Spain
| | - Gunilla Johansson
- Department of Neurobiology, Care sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, Solna, Sweden
| | | | | | - Lena Sannemann
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Psychiatry, Cologne, Germany
| | | | - Miren Gurruchaga Telleria
- Research Center and Memory Clinic, Fundació ACE, Institut Català de Neurociències Aplicades, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Sergi Valero
- Research Center and Memory Clinic, Fundació ACE, Institut Català de Neurociències Aplicades, Universitat Internacional de Catalunya, Barcelona, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Lisa Vermunt
- Amsterdam UMC, VU University, Amsterdam, Amsterdam, the Netherlands
| | - Lisa Waterink
- Amsterdam UMC, VU University, Amsterdam, Amsterdam, the Netherlands
| | - Bengt Winblad
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, Solna, Sweden.,Karolinska University Hospital, Theme Inflammation and Aging, Huddinge, Sweden
| | | | - Marissa Zwan
- Amsterdam UMC, VU University, Amsterdam, Amsterdam, the Netherlands
| | - Mercè Boada
- Fundació ACE (FACE), Barcelona, Spain.,Research Center and Memory Clinic, Fundació ACE, Institut Català de Neurociències Aplicades, Universitat Internacional de Catalunya, Barcelona, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
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7
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Jing J, Zhang F, Zhao L, Xie J, Chen J, Zhong R, Zhang Y, Dong C. Correlation Between Brain 18F-AV45 and 18F-FDG PET Distribution Characteristics and Cognitive Function in Patients with Mild and Moderate Alzheimer's Disease. J Alzheimers Dis 2021; 79:1317-1325. [PMID: 33427748 DOI: 10.3233/jad-201335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Florbetapir (AV45) and fluorodeoxyglucose (FDG) PET imaging are valuable techniques to detect the amyloid-β (Aβ) load and brain glucose metabolism in patients with Alzheimer's disease (AD). OBJECTIVE The purpose of this study is to access the characteristics of Aβ load and FDG metabolism in brain for further investigating their relationships with cognitive impairment in AD patients. METHODS Twenty-seven patients with AD (average 70.6 years old, N = 13 male, N = 14 female) were enrolled in this study. These AD patients underwent the standard clinical assessment and received detailed imaging examinations of the nervous system by using Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MOCA), 18F-AV45, and 18F-FDG PET scans. RESULTS Of 27 AD patients, 22 patients (81.5%) showed significantly increases in Aβ load and 26 patients (96.3%) had significantly reductions in FDG metabolism. The moderate AD patients had more brain areas of reduced FDG metabolism and more severe reductions in some regions compared to mild AD patients, with no differences in Aβ load observed. Moreover, the range and degree of reduced FDG metabolism in several regions were positively correlated with the total score of MMSE or MOCA, whereas the range of Aβ load did not. No correlation was found between the range of Aβ load and the range of reduced FDG metabolism in this study. CONCLUSION The reduction in FDG metabolisms captured by 18F-FDG imaging can be used as a potential biomarker for AD diagnosis in the future. 18F-AV45 imaging did not present valuable evidence for evaluating AD patient in this study.
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Affiliation(s)
- Jiaojiao Jing
- Department of Neurology, the First Affiliated Hospital, Dalian Medical University, Dalian, China
| | - Feng Zhang
- Department of Neurology, the First Affiliated Hospital, Dalian Medical University, Dalian, China.,First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Li Zhao
- Department of Neurology, the First Affiliated Hospital, Dalian Medical University, Dalian, China
| | - Jinghui Xie
- Department of Nuclear Medicine, the First Affiliated Hospital, Dalian Medical University, Dalian, China
| | - Jianwen Chen
- Department of Neurology, the First Affiliated Hospital, Dalian Medical University, Dalian, China
| | - Rujia Zhong
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Yanjun Zhang
- Department of Nuclear Medicine, the First Affiliated Hospital, Dalian Medical University, Dalian, China
| | - Chunbo Dong
- Department of Neurology, the First Affiliated Hospital, Dalian Medical University, Dalian, China
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8
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A critical review of radiotracers in the positron emission tomography imaging of traumatic brain injury: FDG, tau, and amyloid imaging in mild traumatic brain injury and chronic traumatic encephalopathy. Eur J Nucl Med Mol Imaging 2020; 48:623-641. [DOI: 10.1007/s00259-020-04926-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 06/11/2020] [Indexed: 12/14/2022]
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9
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Proven validity and management impact of amyloid imaging in Alzheimer’s disease—repetita juvant. Eur J Nucl Med Mol Imaging 2020; 47:1787-1790. [DOI: 10.1007/s00259-020-04742-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Alavi A, Barrio JR, Werner TJ, Khosravi M, Newberg A, Høilund-Carlsen PF. Suboptimal validity of amyloid imaging-based diagnosis and management of Alzheimer’s disease: why it is time to abandon the approach. Eur J Nucl Med Mol Imaging 2019; 47:225-230. [DOI: 10.1007/s00259-019-04564-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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11
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Khosravi M, Peter J, Wintering NA, Serruya M, Shamchi SP, Werner TJ, Alavi A, Newberg AB. 18F-FDG Is a Superior Indicator of Cognitive Performance Compared to 18F-Florbetapir in Alzheimer’s Disease and Mild Cognitive Impairment Evaluation: A Global Quantitative Analysis. J Alzheimers Dis 2019; 70:1197-1207. [DOI: 10.3233/jad-190220] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Mohsen Khosravi
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jonah Peter
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Nancy A. Wintering
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, USA
| | - Mijail Serruya
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Thomas J. Werner
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Abass Alavi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Andrew B. Newberg
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, USA
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13
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Samra GK, Dang K, Ho H, Baranwal A, Mukherjee J. Dual targeting agents for Aβ plaque/P-glycoprotein and Aβ plaque/nicotinic acetylcholine α4β2* receptors-potential approaches to facilitate Aβ plaque removal in Alzheimer's disease brain. Med Chem Res 2018; 27:1634-1646. [PMID: 29937677 PMCID: PMC6013267 DOI: 10.1007/s00044-018-2178-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/31/2018] [Indexed: 12/28/2022]
Abstract
Alzheimer's disease (AD) affects 10% of people older than 65 and is characterized by a progressive loss of cognitive function with an abnormal accumulation of amyloid β (Aβ ) plaques and neurofibrillary tangles (NFT) in the brain. Efforts to reduce brain Aβ plaques continue to be investigated as a therapeutic approach for AD. We report here development of dual targeting agents with affinity for Aβ plaque/P-glycoprotein (Pgp) and Aβ plaque/α4β 2* nicotinic acetylcholine receptors (nAChR). These novel dual agents may be able to efflux Aβ plaques via the paravascular (glymphatic) pathways. Ferulic acid (FA), ferulic acid ethyl ester (FAEE), and curcumin (CUR) were used for Aβ plaques, fexofenadine (FEX) was used as substrate for Pgp and nifrolidine (NIF) was used for α4β 2* nAChRs. Aβ plaque/α4β 2* nAChR dual agent, FA-NIF (GKS-007) exhibited IC50 = 3-6 nM for α4β 2* nAChRs in [3H]cytisine-radiolabeled thalamus and frontal cortex in rat brain slices. In postmortem human AD frontal cortex, Aβ plaques labeled with [3H]PIB, FEX-CUR showed a 35% reduction in gray matter (GM)/white matter (WM) [3H]PIB binding, while CUR alone showed a 50% reduction. In vivo biodistribution studies are required of the Aβ-Pgp and Aβ-α4β 2* nAChRs dual targeting agents in order to evaluate their potential as therapeutic approaches for reducing brain Aβ plaques.
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Affiliation(s)
- Gurleen K Samra
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
| | - Kenneth Dang
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
| | - Heather Ho
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
| | - Aparna Baranwal
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
| | - Jogeshwar Mukherjee
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
- Department of Biomedical Engineering, University of California-Irvine, Irvine, CA 92697, USA
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14
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What Can Be and What Cannot Be Accomplished With PET: Rectifying Ongoing Misconceptions. Clin Nucl Med 2018; 42:603-605. [PMID: 28570374 DOI: 10.1097/rlu.0000000000001695] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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15
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Høilund-Carlsen PF, Barrio JR, Gjedde A, Werner TJ, Alavi A. Circular Inference in Dementia Diagnostics. J Alzheimers Dis 2018; 63:69-73. [DOI: 10.3233/jad-180050] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Poul F. Høilund-Carlsen
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Jorge R. Barrio
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA, USA
| | - Albert Gjedde
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Thomas J. Werner
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Abass Alavi
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
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16
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Promteangtrong C, Kolber M, Ramchandra P, Moghbel M, Houshmand S, Schöll M, Werner TJ, Alavi A, Buchpiguel C. Multimodality Imaging Approaches in Alzheimer's disease. Part II: 1H MR spectroscopy, FDG PET and Amyloid PET. Dement Neuropsychol 2015; 9:330-342. [PMID: 29213982 PMCID: PMC5619315 DOI: 10.1590/1980-57642015dn94000330] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/17/2015] [Indexed: 01/01/2023] Open
Abstract
In this Part II review, as a complement to the Part I published in this supplement, the authors cover the imaging techniques that evaluates the Alzheimer's disease according to the different metabolic and molecular profiles. In this section MR spectroscopy, FDG-PET and amyloid PET are deeply discussed.
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Affiliation(s)
| | - Marcus Kolber
- Department of Radiology, University of Pennsylvania
School of Medicine, Philadelphia, Pennsylvania, USA
| | - Priya Ramchandra
- Department of Radiology, University of Pennsylvania
School of Medicine, Philadelphia, Pennsylvania, USA
| | - Mateen Moghbel
- Stanford University School of Medicine, Stanford,
California
| | - Sina Houshmand
- Department of Radiology, University of Pennsylvania
School of Medicine, Philadelphia, Pennsylvania, USA
| | - Michael Schöll
- Karolinska Institutet, Alzheimer Neurobiology Center,
Stockholm, Sweden
| | - Thomas J. Werner
- Department of Radiology, University of Pennsylvania
School of Medicine, Philadelphia, Pennsylvania, USA
| | - Abass Alavi
- Department of Radiology, University of Pennsylvania
School of Medicine, Philadelphia, Pennsylvania, USA
| | - Carlos Buchpiguel
- Nuclear Medicine Service, Instituto do Cancer do Estado
de São Paulo, University of São Paulo, São Paulo, Brazil
- Nuclear Medicine Center, Radiology Institute, University
of São Paulo General Hospital , São Paulo, Brazil
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Donaghy P, Thomas AJ, O'Brien JT. Amyloid PET Imaging in Lewy body disorders. Am J Geriatr Psychiatry 2015; 23:23-37. [PMID: 23831180 DOI: 10.1016/j.jagp.2013.03.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 02/19/2013] [Accepted: 03/01/2013] [Indexed: 11/25/2022]
Abstract
Lewy body (LB) disorders, including Parkinson disease (PD), Parkinson disease dementia (PDD), and dementia with Lewy bodies (DLB), are the second most common type of neurodegenerative dementia. Although the pathological hallmarks of LB disorders are Lewy bodies and Lewy neurites, cortical amyloid-beta (Aβ) deposition is also often seen. The relationship between Aβ pathology and dementia in LB disorders is unclear. Recently, positron emission tomography Aβ ligands have been developed that enable in vivo imaging of Aβ. In this paper we review amyloid imaging studies in LB disorders. LB disorders are associated with lower mean cortical Aβ ligand binding compared with Alzheimer disease. In DLB and PDD many subjects have normal levels of cortical Aβ, though a subset show increased Aβ ligand binding. Those with DLB show greater ligand binding than PDD; binding does not appear to be increased in PD without dementia. Cortical Aβ deposition may be a factor in the development of cognitive impairment in some cases of dementia in LB disorders. Amyloid imaging is of limited use in the diagnosis of LB disorders but Aβ deposition may predict the future development of dementia in PD. Reports of correlation between Aβ deposition and symptom profile, severity, and progression have been inconsistent. Some results suggest a synergistic interaction between Aβ and α-synuclein. Interpretation of the current evidence is hampered by differing methodologies across studies and small sample sizes. Large, prospective longitudinal studies are needed to clarify the association of Aβ with symptom development, progression, severity, and treatment response in LB disorders.
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Affiliation(s)
- Paul Donaghy
- Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom.
| | - Alan J Thomas
- Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, United Kingdom
| | - John T O'Brien
- Department of Psychiatry, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
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Kepe V, Moghbel MC, Långström B, Zaidi H, Vinters HV, Huang SC, Satyamurthy N, Doudet D, Mishani E, Cohen RM, Høilund-Carlsen PF, Alavi A, Barrio JR. Amyloid-β positron emission tomography imaging probes: a critical review. J Alzheimers Dis 2014; 36:613-31. [PMID: 23648516 DOI: 10.3233/jad-130485] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The rapidly rising prevalence and cost of Alzheimer's disease in recent decades has made the imaging of amyloid-β deposits the focus of intense research. Several amyloid imaging probes with purported specificity for amyloid-β plaques are currently at various stages of FDA approval. However, a number of factors appear to preclude these probes from clinical utilization. As the available "amyloid specific" positron emission tomography imaging probes have failed to demonstrate diagnostic value and have shown limited utility for monitoring therapeutic interventions in humans, a debate on their significance has emerged. The aim of this review is to identify and discuss critically the scientific issues contributing to the extensive inconsistencies reported in the literature on their purported in vivo amyloid specificity and potential utilization in patients.
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Affiliation(s)
- Vladimir Kepe
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California-Los Angeles, CA 90095, USA
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Hess S, Blomberg BA, Zhu HJ, Høilund-Carlsen PF, Alavi A. The pivotal role of FDG-PET/CT in modern medicine. Acad Radiol 2014; 21:232-49. [PMID: 24439337 DOI: 10.1016/j.acra.2013.11.002] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 10/30/2013] [Accepted: 11/01/2013] [Indexed: 12/21/2022]
Abstract
The technology behind positron emission tomography (PET) and the most widely used tracer, 2-deoxy-2-[18F]fluoro-D-glucose (FDG), were both conceived in the 1970s, but the latest decade has witnessed a rapid emergence of FDG-PET as an effective imaging technique. This is not least due to the emergence of hybrid scanners combining PET with computed tomography (PET/CT). Molecular imaging has enormous potential for advancing biological research and patient care, and FDG-PET/CT is currently the most widely used technology in this domain. In this review, we discuss contemporary applications of FDG-PET and FDG-PET/CT as well as novel developments in quantification and potential future indications including the emerging new modality PET/magnetic resonance imaging.
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Abstract
As radiologists, our role in the workup of the dementia patient has long been limited by the sensitivity of our imaging tools and lack of effective treatment options. Over the past 30 years, we have made tremendous strides in understanding the genetic, molecular, and cellular basis of Alzheimer disease (AD). We now know that the pathologic features of AD are present 1 to 2 decades prior to development of symptoms, though currently approved symptomatic therapies are administered much later in the disease course. The search for true disease-modifying therapy continues and many clinical trials are underway. Current outcome measures, based on cognitive tests, are relatively insensitive to pathologic disease progression, requiring long, expensive trials with large numbers of participants. Biomarkers, including neuroimaging, have great potential to increase the power of trials by matching imaging methodology with therapeutic mechanism. One of the most important advances over the past decade has been the development of in vivo imaging probes targeted to amyloid beta protein, and one agent is already available for clinical use. Additional advances include automated volumetric imaging methods to quantitate cerebral volume loss. Use of such techniques in small, early phase trials are expected to significantly increase the number and quality of candidate drugs for testing in larger trials. In addition to a critical role in trials, structural, molecular, and functional imaging techniques can give us a window on the etiology of AD and other neurodegenerative diseases. This combination of developments has potential to bring diagnostic radiology to the forefront in AD research, therapeutic trials, and patient care.
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Affiliation(s)
- Jeffrey R Petrella
- From the Division of Neuroradiology, Duke University Medical Center, DUMC-Box 3808, Durham, NC
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Ni R, Gillberg PG, Bergfors A, Marutle A, Nordberg A. Amyloid tracers detect multiple binding sites in Alzheimer's disease brain tissue. Brain 2013; 136:2217-27. [PMID: 23757761 DOI: 10.1093/brain/awt142] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Imaging fibrillar amyloid-β deposition in the human brain in vivo by positron emission tomography has improved our understanding of the time course of amyloid-β pathology in Alzheimer's disease. The most widely used amyloid-β imaging tracer so far is (11)C-Pittsburgh compound B, a thioflavin derivative but other (11)C- and (18)F-labelled amyloid-β tracers have been studied in patients with Alzheimer's disease and cognitively normal control subjects. However, it has not yet been established whether different amyloid tracers bind to identical sites on amyloid-β fibrils, offering the same ability to detect the regional amyloid-β burden in the brains. In this study, we characterized (3)H-Pittsburgh compound B binding in autopsied brain regions from 23 patients with Alzheimer's disease and 20 control subjects (aged 50 to 88 years). The binding properties of the amyloid tracers FDDNP, AV-45, AV-1 and BF-227 were also compared with those of (3)H-Pittsburgh compound B in the frontal cortices of patients with Alzheimer's disease. Saturation binding studies revealed the presence of high- and low-affinity (3)H-Pittsburgh compound B binding sites in the frontal cortex (K(d1): 3.5 ± 1.6 nM; K(d2): 133 ± 30 nM) and hippocampus (K(d1):5.6 ± 2.2 nM; K(d2): 181 ± 132 nM) of Alzheimer's disease brains. The relative proportion of high-affinity to low-affinity sites was 6:1 in the frontal cortex and 3:1 in the hippocampus. One control showed both high- and low-affinity (3)H-Pittsburgh compound B binding sites (K(d1): 1.6 nM; K(d2): 330 nM) in the cortex while the others only had a low-affinity site (K(d2): 191 ± 70 nM). (3)H-Pittsburgh compound B binding in Alzheimer's disease brains was higher in the frontal and parietal cortices than in the caudate nucleus and hippocampus, and negligible in the cerebellum. Competitive binding studies with (3)H-Pittsburgh compound B in the frontal cortices of Alzheimer's disease brains revealed high- and low-affinity binding sites for BTA-1 (Ki: 0.2 nM, 70 nM), florbetapir (1.8 nM, 53 nM) and florbetaben (1.0 nM, 65 nM). BF-227 displaced 83% of (3)H-Pittsburgh compound B binding, mainly at a low-affinity site (311 nM), whereas FDDNP only partly displaced (40%). We propose a multiple binding site model for the amyloid tracers (binding sites 1, 2 and 3), where AV-45 (florbetapir), AV-1 (florbetaben), and Pittsburgh compound B, all show nanomolar affinity for the high-affinity site (binding site 1), as visualized by positron emission tomography. BF-227 shows mainly binding to site 3 and FDDNP shows only some binding to site 2. Different amyloid tracers may provide new insight into the pathophysiological mechanisms in the progression of Alzheimer's disease.
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Affiliation(s)
- Ruiqing Ni
- Alzheimer Neurobiology Centre, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
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Torosyan N, Silverman DHS. Neuronuclear imaging in the evaluation of dementia and mild decline in cognition. Semin Nucl Med 2013; 42:415-22. [PMID: 23026363 DOI: 10.1053/j.semnuclmed.2012.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Recently, the National Institute on Aging and the Alzheimer's Association identified specific structural and functional neuroimaging findings as valuable markers of biological processes occurring in the human brain, especially processes that herald impending dementia caused by Alzheimer's disease (AD) in its prodromal form. In particular, the imaging modalities of magnetic resonance imaging and positron emission tomography (PET) were singled out, along with certain biomarkers in cerebrospinal fluid, to serve this purpose. We review the clinical tests available for neuropsychologic evaluation and in cases when the differential diagnosis for the causes of cognitive impairment is difficult to make, we consider biomarkers, beginning with cerebrospinal fluid, for assessment of cognitive decline. For more direct information on dementia-related pathologic changes in brain tissue, structural features observed in magnetic resonance imaging scans are regarded. We next discuss the use of single-photon emission computed tomography for evaluating functional changes. Then, pertinent to the recent National Institute on Aging and the Alzheimer's Association's consensus statement on the diagnosis of prodromal AD, we focus on assessing the cerebral metabolic changes associated with neurodegenerative diseases that are identified with fluorodeoxyglucose PET, as well as consider the most appropriate roles for amyloid imaging based on recent studies examining the use of PET with tracers having higher retention in brain tissue-harboring plaques composed of insoluble beta-amyloid. We also consider the leading causes for the current underuse of neuronuclear imaging in evaluating patients with cognitive problems, along with strategies for combating them. Finally, we suggest an overall diagnostic algorithm to guide optimal use of all the neuroimaging tools in assessing patients with cognitive decline.
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Affiliation(s)
- Nare Torosyan
- Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at the University of California, Los Angeles, CA 90095-7370, USA
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Hickey JL, Donnelly PS. Diagnostic imaging of Alzheimer's disease with copper and technetium complexes. Coord Chem Rev 2012. [DOI: 10.1016/j.ccr.2012.03.035] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Villemagne VL, Klunk WE, Mathis CA, Rowe CC, Brooks DJ, Hyman BT, Ikonomovic MD, Ishii K, Jack CR, Jagust WJ, Johnson KA, Koeppe RA, Lowe VJ, Masters CL, Montine TJ, Morris JC, Nordberg A, Petersen RC, Reiman EM, Selkoe DJ, Sperling RA, Van Laere K, Weiner MW, Drzezga A. Aβ Imaging: feasible, pertinent, and vital to progress in Alzheimer's disease. Eur J Nucl Med Mol Imaging 2012; 39:209-19. [PMID: 22218879 PMCID: PMC3261395 DOI: 10.1007/s00259-011-2045-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Gao M, Wang M, Zheng QH. Facile synthesis of carbon-11-labeled arylpiperazinylthioalkyl derivatives as new PET radioligands for imaging of 5-HT1AR. Appl Radiat Isot 2012; 70:498-504. [DOI: 10.1016/j.apradiso.2011.11.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 10/26/2011] [Accepted: 11/14/2011] [Indexed: 11/15/2022]
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