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Pontecorvo MJ, Devous MD, Kennedy I, Navitsky M, Lu M, Galante N, Salloway S, Doraiswamy PM, Southekal S, Arora AK, McGeehan A, Lim NC, Xiong H, Truocchio SP, Joshi AD, Shcherbinin S, Teske B, Fleisher AS, Mintun MA. A multicentre longitudinal study of flortaucipir (18F) in normal ageing, mild cognitive impairment and Alzheimer's disease dementia. Brain 2020; 142:1723-1735. [PMID: 31009046 PMCID: PMC6536847 DOI: 10.1093/brain/awz090] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [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: 09/12/2018] [Revised: 01/11/2019] [Accepted: 02/06/2019] [Indexed: 01/20/2023] Open
Abstract
The advent of tau-targeted PET tracers such as flortaucipir (18F) (flortaucipir, also known as 18F-AV-1451 or 18F-T807) have made it possible to investigate the sequence of development of tau in relationship to age, amyloid-β, and to the development of cognitive impairment due to Alzheimer's disease. Here we report a multicentre longitudinal evaluation of the relationships between baseline tau, tau change and cognitive change, using flortaucipir PET imaging. A total of 202 participants 50 years old or older, including 57 cognitively normal subjects, 97 clinically defined mild cognitive impairment and 48 possible or probable Alzheimer's disease dementia patients, received flortaucipir PET scans of 20 min in duration beginning 80 min after intravenous administration of 370 MBq flortaucipir (18F). On separate days, subjects also received florbetapir amyloid PET imaging, and underwent a neuropsychological test battery. Follow-up flortaucipir scans and neuropsychological battery assessments were also performed at 9 and 18 months. Fifty-five amyloid-β+ and 90 amyloid-β- subjects completed the baseline and 18-month study visits and had valid quantifiable flortaucipir scans at both time points. There was a statistically significant increase in the global estimate of cortical tau burden as measured by standardized uptake value ratio (SUVr) from baseline to 18 months in amyloid-β+ but not amyloid-β- subjects (least squared mean change in flortaucipir SUVr : 0.0524 ± 0.0085, P < 0.0001 and 0.0007 ± 0.0024 P = 0.7850, respectively), and a significant association between magnitude of SUVr increase and baseline tau burden. Voxel-wise evaluations further suggested that the regional pattern of change in flortaucipir PET SUVr over the 18-month study period (i.e. which regions exhibited the greatest change) also varied as a function of baseline global estimate of tau burden. In subjects with lower global SUVr, temporal lobe regions showed the greatest flortaucipir retention, whereas in subjects with higher baseline SUVr, parietal and frontal regions were increasingly affected. Finally, baseline flortaucipir and change in flortaucipir SUVr were both significantly (P < 0.0001) associated with changes in cognitive performance. Taken together, these results provide a preliminary characterization of the longitudinal spread of tau in Alzheimer's disease and suggest that the amount and location of tau may have implications both for the spread of tau and the cognitive deterioration that may occur over an 18-month period.
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Affiliation(s)
| | | | - Ian Kennedy
- Avid Radiopharmaceuticals, Philadelphia, PA, USA
| | | | - Ming Lu
- Avid Radiopharmaceuticals, Philadelphia, PA, USA
| | | | | | | | | | | | | | | | - Hui Xiong
- Avid Radiopharmaceuticals, Philadelphia, PA, USA
| | | | | | | | | | | | - Mark A Mintun
- Avid Radiopharmaceuticals, Philadelphia, PA, USA.,Eli Lilly and Company, Indianapolis IN, USA
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Mintun MA, Devous MD, Lu M, Pontecorvo MJ, Joshi AD, Southekal S, Siderowf A, Lowrey M, Devine M, Benedum TE, Pearson C, Lim NC, Case MG, Sundell KL, Siemers ER. [O5–01–01]: PET BIOMARKERS IN THE EXPEDITION 3 TRIAL OF PATIENTS WITH MILD AD. Alzheimers Dement 2017. [DOI: 10.1016/j.jalz.2017.07.506] [Citation(s) in RCA: 1] [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: 10/18/2022]
Affiliation(s)
- Mark A. Mintun
- Avid RadiopharmaceuticalsPhiladelphiaPAUSA
- Eli Lilly and CompanyIndianapolisINUSA
| | | | - Ming Lu
- Avid RadiopharmaceuticalsPhiladelphiaPAUSA
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Pontecorvo MJ, Devous MD, Navitsky M, Lu M, Salloway S, Schaerf FW, Jennings D, Arora AK, McGeehan A, Lim NC, Xiong H, Joshi AD, Siderowf A, Mintun MA. Relationships between flortaucipir PET tau binding and amyloid burden, clinical diagnosis, age and cognition. Brain 2017; 140:748-763. [PMID: 28077397 PMCID: PMC5382945 DOI: 10.1093/brain/aww334] [Citation(s) in RCA: 172] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 11/03/2016] [Indexed: 01/21/2023] Open
Abstract
The advent of tau-targeted positron emission tomography tracers such as flortaucipir (18F-AV-1451, also known as 18F-T807) have made it possible to investigate the sequence of development of tau and amyloid-β in relationship to age, and to the development of cognitive impairment due to Alzheimer's disease. In this study, flortaucipir tau and florbetapir amyloid positron emission tomography were obtained for 217 subjects including 16 young and 58 older cognitively normal subjects, 95 subjects with mild cognitive impairment (Mini-Mental State Examination 24-30) and 48 subjects with clinically-defined possible or probable Alzheimer's disease (Mini-Mental State Examination >10). Images were evaluated visually and quantitatively by regional and voxel-based cortical to cerebellar standard uptake value ratios. For amyloid positron emission tomography positive (Aβ+) subjects, flortaucipir neocortical standard uptake value ratio was significantly higher with more advanced clinical stage (Alzheimer's disease > mild cognitive impairment > older cognitively normal) and was significantly elevated for Aβ+ mild cognitive impairment and Alzheimer's disease subjects relative to the respective Aβ- subjects. In contrast, florbetapir Aβ- older cognitively normal subjects showed an increase in flortaucipir standard uptake value ratios in mesial temporal lobe regions (amygdala, hippocampus/choroid plexus region of interest) compared to younger cognitively normal subjects, but no increased standard uptake value ratios in neocortical regions. Analysis of covariance with planned contrasts showed no differences in regional or composite posterior neocortical flortaucipir standard uptake value ratio as a function of diagnostic group among Aβ- older cognitively normal or clinically diagnosed Alzheimer's disease or mild cognitive impairment subjects. The pattern of flortaucipir distribution among Aβ+ subjects was reminiscent of the cross-sectional distribution of tau reported in post-mortem pathology studies, in that the most commonly affected regions were the inferior and lateral temporal lobes, the same regions where the first signs of increased retention appeared in Aβ+ cognitively normal subjects. However, there was large variability in extent/density of flortaucipir tau binding among Aβ+ subjects. Although high neocortical flortaucipir retention was consistently associated with an Aβ+ florbetapir positron emission tomography scan, not all Aβ+ subjects had elevated flortaucipir standard uptake value ratios. Finally, within the Aβ+ group, increasing levels of flortaucipir tau binding were associated with increased cognitive impairment, as assessed by Mini-Mental State Examination and Alzheimer's Disease Assessment Scale. These results suggest development of tau beyond the mesial temporal lobe is associated with, and may be dependent on, amyloid accumulation. Further, the results are consistent with the hypothesis that cortical tau is associated with cognitive impairment.
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Affiliation(s)
| | | | | | - Ming Lu
- Avid Radiopharmaceuticals, Philadelphia, PA 19104, USA
| | | | - Frederick W Schaerf
- Neuropsychiatric Research Center of Southwest Florida, Fort Myers, FL 33912, USA
| | | | - Anupa K Arora
- Avid Radiopharmaceuticals, Philadelphia, PA 19104, USA
| | - Anne McGeehan
- Avid Radiopharmaceuticals, Philadelphia, PA 19104, USA
| | | | - Hui Xiong
- Avid Radiopharmaceuticals, Philadelphia, PA 19104, USA
| | | | | | - Mark A Mintun
- Avid Radiopharmaceuticals, Philadelphia, PA 19104, USA
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Xiong H, Hoye AT, Fan KH, Li X, Clemens J, Horchler CL, Lim NC, Attardo G. Facile Route to 2-Fluoropyridines via 2-Pyridyltrialkylammonium Salts Prepared from Pyridine N-Oxides and Application to 18F-Labeling. Org Lett 2015; 17:3726-9. [DOI: 10.1021/acs.orglett.5b01703] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Hui Xiong
- Avid Radiopharmaceuticals, 3711 Market Street, Philadelphia, Pennsylvania 19104, United States
| | - Adam T. Hoye
- Avid Radiopharmaceuticals, 3711 Market Street, Philadelphia, Pennsylvania 19104, United States
| | - Kuo-Hsien Fan
- Avid Radiopharmaceuticals, 3711 Market Street, Philadelphia, Pennsylvania 19104, United States
| | - Ximin Li
- Avid Radiopharmaceuticals, 3711 Market Street, Philadelphia, Pennsylvania 19104, United States
| | - Jennifer Clemens
- Avid Radiopharmaceuticals, 3711 Market Street, Philadelphia, Pennsylvania 19104, United States
| | - Carey L. Horchler
- Avid Radiopharmaceuticals, 3711 Market Street, Philadelphia, Pennsylvania 19104, United States
| | - Nathaniel C. Lim
- Avid Radiopharmaceuticals, 3711 Market Street, Philadelphia, Pennsylvania 19104, United States
| | - Giorgio Attardo
- Avid Radiopharmaceuticals, 3711 Market Street, Philadelphia, Pennsylvania 19104, United States
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Bowen ML, Lim NC, Ewart CB, Misri R, Ferreira CL, Häfeli U, Adam MJ, Orvig C. Glucosamine conjugates bearing N,N,O-donors: potential imaging agents utilizing the [M(CO)3]+ core (M = Re, Tc). Dalton Trans 2009:9216-27. [DOI: 10.1039/b914310f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lim NC, Pavlova SV, Brückner C. Squaramide Hydroxamate-Based Chemidosimeter Responding to Iron(III) with a Fluorescence Intensity Increase. Inorg Chem 2008; 48:1173-82. [DOI: 10.1021/ic801322x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nathaniel C. Lim
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060
| | - Svetlana V. Pavlova
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060
| | - Christian Brückner
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060
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Lim NC, Ewart CB, Bowen ML, Ferreira CL, Barta CA, Adam MJ, Orvig C. Pyridine−tert-Nitrogen−Phenol Ligands: N,N,O-Type Tripodal Chelates for the [M(CO)3]+ Core (M = Re, Tc). Inorg Chem 2008; 47:1337-45. [DOI: 10.1021/ic701822n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Nathaniel C. Lim
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1, and TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - Charles B. Ewart
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1, and TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - Meryn L. Bowen
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1, and TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - Cara L. Ferreira
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1, and TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - Cheri A. Barta
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1, and TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - Michael J. Adam
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1, and TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1, and TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
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Abstract
Zinc is the second most abundant transition metal in the human body, fulfilling a multitude of biological roles, but the mechanisms underlying its physiology are poorly understood. The lack of knowledge is, in part, due to the hitherto limited techniques available to track zinc in biological systems. The recent emergence of a number of zinc-specific molecular sensors has provided a new tool to image zinc in live cells and tissue samples. This contribution highlights the concepts behind using zinc-specific fluorescent molecular sensors to gain information about zinc action in biological samples, and provides representative examples of images recorded.
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Affiliation(s)
- Nathaniel C Lim
- Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060, USA
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Lim NC, Schuster JV, Porto MC, Tanudra MA, Yao L, Freake HC, Brückner C. Coumarin-Based Chemosensors for Zinc(II): Toward the Determination of the Design Algorithm for CHEF-Type and Ratiometric Probes. Inorg Chem 2005; 44:2018-30. [PMID: 15762729 DOI: 10.1021/ic048905r] [Citation(s) in RCA: 259] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of a series of coumarin-based chemosensor assemblies for zinc is detailed, using established and novel synthetic pathways. Variations of the nature of the chelating unit (DPA or cyclen), position of the attachment point of the chelating unit (3- or 4-position), and nature of the 7-substituent (-OH, -OAc, or -NR2) on the coumarin play a crucial role in whether, and to what extent, a CHEF-type or ratiometric response of the chemosensor is observed. Solvent effects are also discussed. The chemosensors were shown to be competent for detecting zinc pools in cultured rat pituitary (GH3) and hepatoma (H4IIE) cell lines. The work further defines the design algorithms for zinc-selective CHEF-type and ratiometric chemosensors.
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Affiliation(s)
- Nathaniel C Lim
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, USA
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Lim NC, Brückner C. DPA-substituted coumarins as chemosensors for zinc(ii): modulation of the chemosensory characteristics by variation of the position of the chelate on the coumarin. Chem Commun (Camb) 2004:1094-5. [PMID: 15116201 DOI: 10.1039/b403448a] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The sensory capabilities of two novel di(2-picolyl)amine (DPA)-substituted coumarins are described and it is shown that the variation of the point of attachment of the DPA group to the coumarin framework controls their sensing behavior: the 4-substituted system is a CHEF-type sensor that shows a significant increase in fluorescence intensity upon Zn(2+) binding, whereas the 3-substituted system is a ratiometric sensor.
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Affiliation(s)
- Nathaniel C Lim
- Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060, USA
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Lim NC, Morton MD, Jenkins HA, Brückner C. Squaric Acid N-Hydroxylamides: Synthesis, Structure, and Properties of Vinylogous Hydroxamic Acid Analogues. J Org Chem 2003; 68:9233-41. [PMID: 14629141 DOI: 10.1021/jo035175g] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [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: 11/28/2022]
Abstract
The synthesis of squaric acid N-hydroxylamide esters 5 and amides 6 from dimethyl squarate 2a is described. These derivatives are analogues of the naturally occurring iron(III) chelator hydroxamic acid. On the basis of a comparative reactivity study, a concerted retro-Cope mechanism for the formation of the N-hydroxylamide esters 5 by reaction of dimethyl squarate with hydroxylamines is proposed. A preliminary iron(III) binding study of these hydroxamic acid analogues is presented, demonstrating binding of iron(III) to amides 6 in aqueous solutions, while the esters 5 did not show any sign of metal ion binding. 13C NMR spectroscopic data (chemical shift and spin-lattice relaxation time determination) of these and related derivatives delineate the resonance structures predominant in these molecules. The resonance structures of the derivatives rationalize their spectroscopic data, chemical reactivity, and iron(III) binding properties. Single-crystal X-ray structure analyses of squaric acid N-hydroxylamide ester 5b and squaric acid N-hydroxylamide amide 6c confirm their connectivity and provide structural evidence supporting the spectroscopically derived conclusions. The squaric acid N-hydroxylamides are potentially useful in the construction of chemosensors for iron(III).
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Affiliation(s)
- Nathaniel C Lim
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, USA
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Abstract
The synthesis of a coumarin-cyclen conjugate-based zinc-specific chemosensor and its ability to sense Zn(2+) in vitro is described. Using fluorescence microscopy, the chemosensor was shown to be capable of imaging Zn(2+) in live rat pituitary tumour cells.
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Affiliation(s)
- Nathaniel C Lim
- University of Connecticut, Department of Chemistry, 06269-3060, Storrs, CT, USA
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