1
|
Labelling with positron emitters of pnicogens and chalcogens. J Labelled Comp Radiopharm 2017; 61:179-195. [DOI: 10.1002/jlcr.3574] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/07/2017] [Accepted: 09/29/2017] [Indexed: 11/07/2022]
|
2
|
Sawant SD, Hudwekar AD, Aravinda Kumar K, Venkateswarlu V, Singh PP, Vishwakarma RA. Ligand- and base-free synthesis of phenols by rapid oxidation of arylboronic acids using iron(III) oxide. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2013.12.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
3
|
Kabalka GW, Green JF, Mccollum G. The synthesis of a polymeric organoborane for the preparation of [15O]-butanol. J Labelled Comp Radiopharm 2011. [DOI: 10.1002/jlcr.2580260132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
4
|
Li Z, Conti PS. Radiopharmaceutical chemistry for positron emission tomography. Adv Drug Deliv Rev 2010; 62:1031-51. [PMID: 20854860 DOI: 10.1016/j.addr.2010.09.007] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 09/11/2010] [Accepted: 09/13/2010] [Indexed: 12/13/2022]
Abstract
Molecular imaging is an emerging technology that allows the visualization of interactions between molecular probes and biological targets. Molecules that either direct or are subject to homeostatic controls in biological systems could be labeled with the appropriate radioisotopes for the quantitative measurement of selected molecular interactions during normal tissue homeostasis and again after perturbations of the normal state. In particular, positron emission tomography (PET) offers picomolar sensitivity and is a fully translational technique that requires specific probes radiolabeled with a usually short-lived positron-emitting radionuclide. PET has provided the capability of measuring biological processes at the molecular and metabolic levels in vivo by the detection of the gamma rays formed as a result of the annihilation of the positrons emitted. Despite the great wealth of information that such probes can provide, the potential of PET strongly depends on the availability of suitable PET radiotracers. However, the development of new imaging probes for PET is far from trivial and radiochemistry is a major limiting factor for the field of PET. In this review, we provided an overview of the most common chemical approaches for the synthesis of PET-labeled molecules and highlighted the most recent developments and trends. The discussed PET radionuclides include ¹¹C (t₁(/)₂=20.4min), ¹³N (t₁(/)₂=9.9min), ¹⁵O (t₁(/)₂=2min), ⁶⁸Ga (t₁(/)₂=68min), ¹⁸F (t₁(/)₂=109.8min), ⁶⁴Cu (t₁(/)₂=12.7h), and ¹²⁴I (t₁(/)₂=4.12d).
Collapse
|
5
|
Miller P, Long N, Vilar R, Gee A. Synthese von11C-,18F-,15O- und13N-Radiotracern für die Positronenemissionstomographie. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200800222] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
6
|
Miller P, Long N, Vilar R, Gee A. Synthesis of11C,18F,15O, and13N Radiolabels for Positron Emission Tomography. Angew Chem Int Ed Engl 2008; 47:8998-9033. [DOI: 10.1002/anie.200800222] [Citation(s) in RCA: 726] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
7
|
Motoshima K, Sato A, Yorimitsu H, Oshima K. Efficient Aerobic Oxidation of Phosphines, Phosphites, and Sulfides by Using Trialkylborane. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.2229] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
8
|
Tuckwell W, Bezak E. Calculation of the positron distribution from 15O nuclei formed in nuclear reactions in human tissue during proton therapy. Phys Med Biol 2007; 52:2483-98. [PMID: 17440247 DOI: 10.1088/0031-9155/52/9/010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To measure and verify the dose distribution within a patient during proton therapy, indirect methods must be used. One such method is to use positron emission tomography (PET), which takes advantage of the nuclear reactions that take place between protons and nuclei in the tissue. The dominant nuclear reaction in human muscle tissue involves oxygen nuclei and produces radioactive oxygen-15. Oxygen-15 decays through positron emission, and it is these positrons that go on to annihilate that produce the signal used in the PET technique. Finding the distribution of annihilation points, however, is not analogous to finding the proton dose distribution. The oxygen-15 and positrons travel finite distances within the tissue, blurring the detected PET distribution from the desired proton distribution. Through Monte Carlo modelling, an analysis of the differences between the positron, oxygen-15 and proton distributions has been made. The program SRIM 2003 was used to find the correlation between the three distributions within simulated muscle tissue. Results show that the distal edge of the proton Bragg peak correlates with the detectable positron distribution, which is a section of the dose distribution of interest due to the steep dose gradient and position of adjacent critical structures.
Collapse
Affiliation(s)
- W Tuckwell
- School of Chemistry and Physics, University of Adelaide, Adelaide, South Australia, Australia.
| | | |
Collapse
|
9
|
Yorimitsu H, Murakami Y, Takamatsu H, Nishimura S, Nakamura E. Synthesis and Bioimaging of Positron-Emitting15O-Labeled 2-Deoxy-D-glucose of Two-Minute Half-Life. Chem Asian J 2007; 2:57-65. [PMID: 17441139 DOI: 10.1002/asia.200600271] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In positron emission tomography (PET), which exploits the affinity of a radiopharmaceutical for the target organ, a systematic repertoire of oxygen-15-labeled PET tracers is expected to be useful for bioimaging owing to the ubiquity of oxygen atoms in organic compounds. However, because of the 2-min half-life of 15O, the synthesis of complex biologically active 15O-labeled organic molecules has not yet been achieved. A state-of-the-art synthesis now makes available an 15O-labeled complex organic molecule, 6-[15O]-2-deoxy-D-glucose. Ultrarapid radical hydroxylation of 2,6-dideoxy-6-iodo-D-glucose with molecular oxygen labeled with 15O of two-minute half-life provided the target 15O-labeled molecule. The labeling reaction with 15O was complete in 1.3 min, and the entire operation time starting from the generation of 15O-containing dioxygen by a cyclotron to the purification of the labeled sugar was 7 min. The labeled sugar accumulated in the metabolically active organs as well as in the bladder of mice and rats. 15O-labeling offers the possibility of repetitive scanning and the use of multiple PET tracers in the same body within a short time, and hence should significantly expand the scope of PET studies of small animals.
Collapse
Affiliation(s)
- Hideki Yorimitsu
- Department of Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | | | | | | | | |
Collapse
|
10
|
|
11
|
Yorimitsu H, Murakami Y, Takamatsu H, Nishimura S, Nakamura E. Ultra-rapid Synthesis of15O-Labeled 2-Deoxy-D-glucose for Positron Emission Tomography (PET). Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200500044] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
12
|
Yorimitsu H, Murakami Y, Takamatsu H, Nishimura S, Nakamura E. Ultra‐rapid Synthesis of
15
O‐Labeled 2‐Deoxy‐
D
‐glucose for Positron Emission Tomography (PET). Angew Chem Int Ed Engl 2005; 44:2708-2711. [PMID: 15828042 DOI: 10.1002/anie.200500044] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Hideki Yorimitsu
- University of Tokyo, Department of Chemistry, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, Fax: (+81) 3-5800-6889
| | - Yoshihiro Murakami
- Advanced Technology Platform Research Laboratory, Fujisawa Pharmaceutical Co. Ltd. 5-2-3, Tokodai, Tsukuba, Ibaraki 300-2698, Japan
- The Medical and Pharmacological Research Center Foundation, Wo32, Inoyama-cho, Hakui, Ishikawa 925-0613, Japan
| | - Hiroyuki Takamatsu
- Advanced Technology Platform Research Laboratory, Fujisawa Pharmaceutical Co. Ltd. 5-2-3, Tokodai, Tsukuba, Ibaraki 300-2698, Japan
- The Medical and Pharmacological Research Center Foundation, Wo32, Inoyama-cho, Hakui, Ishikawa 925-0613, Japan
| | - Shintaro Nishimura
- Advanced Technology Platform Research Laboratory, Fujisawa Pharmaceutical Co. Ltd. 5-2-3, Tokodai, Tsukuba, Ibaraki 300-2698, Japan
- The Medical and Pharmacological Research Center Foundation, Wo32, Inoyama-cho, Hakui, Ishikawa 925-0613, Japan
| | - Eiichi Nakamura
- University of Tokyo, Department of Chemistry, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, Fax: (+81) 3-5800-6889
| |
Collapse
|
13
|
Smith DF, Hansen SB, Østergaard L, Gee AD, Danielsen E, Ishizu K, Bender D, Poulsen PH, Gjedde A. [14C]Serotonin uptake and [O-methyl-11C]venlafaxine kinetics in porcine brain. Nucl Med Biol 2001; 28:633-8. [PMID: 11518644 DOI: 10.1016/s0969-8051(01)00230-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As part of our program of developing PET tracers for neuroimaging of psychotropic compounds, venlafaxine, an antidepressant drug, was evaluated. First, we measured in vitro rates of serotonin uptake in synaptosomes prepared from selected regions of porcine brain. Then, we determined the pharmacokinetics of venlafaxine, [O-methyl-11C]-labeled for PET. Synaptosomal studies showed that the active uptake of [14C]5-HT differed markedly between brain regions, with highest rates in hypothalamus, raphé region, and thalamus, and lowest rates in cortex and cerebellum. PET studies showed that the unidirectional rate of uptake of [O-methyl-11C]venlafaxine from blood to brain was highest in the hypothalamus, raphé region, thalamus and basal ganglia and lowest in the cortex and cerebellum. Under normal physiological conditions, the capillary permeability-surface area (PS) product for [O-methyl-11C]venlafaxine could not be estimated, because of complete flow-limitation of the cerebral uptake. Nevertheless, a correlation occurred between the apparent partition volume of the radiotracer and the rate of active uptake of 5-HT in selected regions of the porcine brain. During hypercapnia, limitations of blood-brain transfer were observed, giving PS-products for water that were only ca. 50% higher than those of venlafaxine. Thus, under normal physiological conditions, the rate of uptake of venlafaxine from blood into brain is completely flow-limited.
Collapse
Affiliation(s)
- D F Smith
- Institute for Basic Research in Psychiatry, Department of Biological Psychiatry, Aarhus University Psychiatric Hospital, 8240 Risskov, Denmark.
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Votaw JR, Henry TR, Shoup TM, Hoffman JM, Woodard JL, Goodman MM. Butanol is superior to water for performing positron emission tomography activation studies. J Cereb Blood Flow Metab 1999; 19:982-9. [PMID: 10478649 DOI: 10.1097/00004647-199909000-00005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
[15(O)]Butanol has been shown to be superior to [15(O)]water for measuring cerebral blood flow with positron emission tomography. This work demonstrates that it is also superior for performing activation studies. Data were collected under three conditions: a visual confrontation animal-naming task, nonsense figure size discrimination, and a nonvisual darkroom control task. Time-activity curves (TAC) were obtained for regions known to be activated by the confrontation naming task to compare absolute uptake and the different kinetics of the two tracers. Also, t statistic maps were calculated from the data of 10 subjects for both tracers and compared for magnitude of change and size of activated regions. Peak uptake in the whole-brain TAC were similar for the two tracers. For all regions and conditions, the washout rate of [15(O)]butanol was 41% greater than that of [15(O)]water. At a threshold of 0, the [15(O)]water and [15(O)]butanol percent difference (nonnormalized) and t statistic (global normalization) images are nearly identical, indicating that the same property is being measured with both tracers. The [15(O)]butanol parametric images displayed at a threshold of /t/ = 5 look similar to the [15(O)]water parametric maps displayed at a threshold of /t/ = 4, which is consistent with the observation that t statistic values in [15(O)]butanol images are generally greater. The t statistic values were equal when the [15(O)]butanol parametric map was created from any subset of 6 subjects and the [15(O)]water parametric map was created from all 10 subjects. Fewer subjects need to be studied with [15(O)]butanol to reach the same statistical power as an [15(O)]water-based study.
Collapse
Affiliation(s)
- J R Votaw
- Emory Center for PET and Department of Radiology, Emory University, Atlanta, Georgia, USA
| | | | | | | | | | | |
Collapse
|
15
|
Martin CC, Jerabek PA, Nickerson LD, Fox PT. Effect of partition coefficient, permeability surface product, and radioisotope on the signal-to-noise ratio in PET functional brain mapping: a computer simulation. Hum Brain Mapp 1999; 7:151-60. [PMID: 10194616 PMCID: PMC6873300 DOI: 10.1002/(sici)1097-0193(1999)7:3<151::aid-hbm1>3.0.co;2-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/1997] [Accepted: 09/04/1998] [Indexed: 11/08/2022] Open
Abstract
In this work we use a computer simulation to estimate the magnitude of improvement in the signal-to-noise ratio of PET functional brain mapping studies as a function of partition coefficient and permeability surface product for O-14, F-17, and O-15 labeled flow tracers. A model for signal-to-noise ratio is derived from the Kety model for inert diffusible blood flow tracers. The results of the simulation suggest that moderate increases in partition coefficient and permeability surface product compared with water would lead to an increase in signal-to-noise ratio of a factor of about 3.
Collapse
Affiliation(s)
- C C Martin
- Research Imaging Center, University of Texas Health Science Center, San Antonio 78284, USA.
| | | | | | | |
Collapse
|
16
|
Wik G, Fredrikson M, Fischer H. Evidence of altered cerebral blood-flow relationships in acute phobia. Int J Neurosci 1997; 91:253-63. [PMID: 9394231 DOI: 10.3109/00207459708986381] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Functional cerebral guiding and integrating systems may be revealed by analyzing the covariation of regional cerebral blood flow (rCBF). Positron emission tomography (PET) was used to measure absolute rCBF in 14 volunteers with specific phobia and 6 nonphobic controls, when exposed to videos containing phobia-relevant and neutral scenes. A fear reaction and increased covariation between absolute rCBFs was observed during phobia-relevant as compared to neutral stimulation in phobics only. In controls fear was not elicited and rCBF covariation was not influenced by stimulus condition, being similar to the pattern observed in phobics during neutral stimulation. We suggest the rCBF correlative pattern during phobic fear to reflect fear-related activation of distinct neuronal pathways that involves the amygdala, the thalamus, and the striatum. We theorize that these pathways are activated also by uncontrolled emotions in diverse conditions, like posttraumatic stress disorder, panic disorder, and schizophrenia.
Collapse
Affiliation(s)
- G Wik
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | | | | |
Collapse
|
17
|
Fowler JS, Wolf AP. Working against Time: Rapid Radiotracer Synthesis and Imaging the Human Brain. Acc Chem Res 1997. [DOI: 10.1021/ar960068c] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joanna S. Fowler
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973
| | - Alfred P. Wolf
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973
| |
Collapse
|
18
|
Fredrikson M, Wik G, Annas P, Ericson K, Stone-Elander S. Functional neuroanatomy of visually elicited simple phobic fear: additional data and theoretical analysis. Psychophysiology 1995; 32:43-8. [PMID: 7878168 DOI: 10.1111/j.1469-8986.1995.tb03404.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We investigated central nervous system correlates of simple phobic fear. Regional cerebral blood flow (rCBF) was measured using positron emission tomography (PET) in eight volunteers with symptomatic spider phobia that were exposed to visual phobogenic and neutral stimuli. Diazepam (0.1 mg/kg body weight i.v.) or placebo was administered under double-blind conditions after initial PET scans. The PET scans were then repeated. The presence of fear was confirmed by rating procedures and increased number of nonspecific electrodermal fluctuations and by higher heart rate during phobic than during neutral stimulation. Phobic as compared to neutral stimulation elevated the regional to whole brain (relative) CBF in the secondary visual cortex but reduced relative rCBF in the hippocampus, prefrontal, orbitofrontal, temporopolar, and posterior cingulate cortex. Diazepam treatment did not affect the relative rCBF or the subjective or physiological fear indices. The observed rCBF pattern replicates our previous findings in snake phobics (M. Fredrikson et al. [1993] Psychophysiology, 30, 127-131; G. Wik et al. [1993] Psychiatry Research (Neuroimaging), 50, 15-24) and indicates that fear and anxiety affect cortical areas outside the classic limbic system areas.
Collapse
Affiliation(s)
- M Fredrikson
- Department of Psychiatry and Psychology, Karolinska Institute and Hospital, Stockholm, Sweden
| | | | | | | | | |
Collapse
|
19
|
Abstract
Brain imaging is performed using radiopharmaceuticals by single photon emission computed tomography (SPECT) and positron emission tomography (PET). SPECT and PET radiopharmaceuticals are classified according to blood-brain-barrier permeability, cerebral perfusion and metabolism receptor-binding, and antigen-antibody binding. The blood-brain-barrier (BBB) SPECT agents, such as 99mTcO4-, [99mTc]DTPA, 201TI and [67Ga]citrate are excluded by normal brain cells, but enter into tumor cells because of altered BBB. These agents were used in the earlier period for the detection of brain tumors. SPECT perfusion agents such as [123I]IMP, [99mTc]HMPAO, [99mTc]ECD are lipophilic agents and therefore, diffuse into the normal brain. These tracers have been successfully used to detect various cerebrovascular diseases such as stroke, Parkinson disease, Huntington's disease, epilepsy, dementia, and psychiatric disorders. Xenon-133 and radiolabeled microspheres have been used for the measurement of cerebral blood flow (CBF). Important receptor-binding SPECT radiopharmaceuticals include [123I]QNE, [123I]IBZM, and [123I]iomazenil. These tracers bind to specific receptors in the brain, thus displaying their distribution in various receptor-related cerebral diseases. Radioiodinated monoclonal antibodies were used for the detection of brain tumors. PET radiopharmaceuticals for brain imaging are commonly labeled with positron-emitters such as 11C, 13N, 15O, and 18F, although other radionuclides such as 82Rb, 62Cu and 68Ga also were used. The brain uptake of [13N]glutamate, [68Ga]EDTA and [82Rb]RbCl depends on the BBB permeability, but these are rarely used for brain imaging. Several cerebral perfusion agents have been introduced, of which [15O]water, [13N]ammonia, and [15O]butanol have been used more frequently. Regional CBF has been quantitated by using these tracers in normal and different cerebral disease states. Other perfusion agents include [15O]O2, [11C]CO, [11C]CO2, [18F]fluoromethane, [15O]O2, [11C]butanol, and [62Cu]PTSM. Among the PET cerebral metabolic agents, [18F]fluorodeoxyglucose (FDG) is most commonly used to detect metabolic abnormalities in the brain. Various brain tumors have been graded by [18F]FDG PET. This technique was used to detect epileptic foci by showing increased uptake in the foci during the ictal period and decreased uptake in the interictal period. Differentiation between recurrent tumors and radiation necrosis and the detection of Alzheimer's disease have been made successfully by [18F]FDG PET. Other PET metabolic agents such as [11C]deoxyglucose, and [11C]methylmethionine have drawn attention in the detection of brain tumors. [18F]fluorodopa is a cerebral neurotransmitter agent, which has been found very useful in the detection of Parkinson disease that shows reduced uptake of the tracer in the striatum of the brain.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- G B Saha
- Department of Nuclear Medicine, Cleveland Clinic Foundation, OH 44195-5074
| | | | | |
Collapse
|
20
|
Ingvar M, Eriksson L, Greitz T, Stone-Elander S, Dahlbom M, Rosenqvist G, af Trampe P, von Euler C. Methodological aspects of brain activation studies: cerebral blood flow determined with [15O]butanol and positron emission tomography. J Cereb Blood Flow Metab 1994; 14:628-38. [PMID: 8014210 DOI: 10.1038/jcbfm.1994.78] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In this methodological study, a procedure for measuring regional CBF (rCBF) with positron emission tomography and 15O-labelled tracers is optimized. Four healthy volunteers were subjected to eight studies with use of [15O]butanol as a tracer: four times while reading aloud and four times while reading silently from a phonologically balanced list of single words. The gain from these repeated intra-individual studies of the same activation state (fractionation) was demonstrated in terms of noise-equivalent counts in a phantom study. A computerized brain atlas was used to reformat the images to a common anatomical representation, thereby minimizing the effects of inter- and intra-individual anatomical and positional variations. This allowed the formation of inter- and intra-individual average subtraction images with error estimates. Differences between the two activation states were detected with use of an exploratory significance map based on a paired Student's t test. The results compared well with Friston's method of determining levels of statistical significance. No difference was obtained when comparing results from rCBF images and images generated from measurement of uptake of the tracer. The paradigm chosen for activation was shown to yield a constant activation level during the repeated measurements (i.e., no habituation).
Collapse
Affiliation(s)
- M Ingvar
- Department of Clinical Neurophysiology, Karolinska Institute/Karolinska Hospital, Stockholm, Sweden
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Moerlein SM, Gaehle GG, Lechner KR, Bera RK, Welch MJ. Automated production of oxygen-15 labeled butanol for PET measurement of regional cerebral blood flow. Appl Radiat Isot 1993; 44:1213-8. [PMID: 8401450 DOI: 10.1016/0969-8043(93)90067-k] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Because [15O]butanol is the radiopharmaceutical of choice for PET studies of cerebral perfusion and neurological activation, we have developed a microprocessor-controlled radiosynthetic system for the preparation of this radiotracer in up to ten batches at a time. An IBM-compatible minicomputer was programmed to direct the reaction of molecular [15O]oxygen with tri-(n-butyl)borane bound to alumina, followed by purification of product [15O]butanol via solid phase extraction with C18 Sep-Paks and sterile filtration. Routine batch yields of over 150 mCi were achieved with a preparation turn-around time of 6.0 min. The final product had high radiochemical purity, low chemical impurity, and was sterile and apyrogenic. This radiopharmaceutical production system is reliable and suitable for tracer production in clinical PET imaging centers.
Collapse
Affiliation(s)
- S M Moerlein
- Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO 63110
| | | | | | | | | |
Collapse
|
22
|
Wik G, Fredrikson M, Ericson K, Eriksson L, Stone-Elander S, Greitz T. A functional cerebral response to frightening visual stimulation. Psychiatry Res 1993; 50:15-24. [PMID: 8511220 DOI: 10.1016/0925-4927(93)90020-i] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The defense reaction, a fundamental reflex in the human behavioral response to threat, is characterized by anxiety and increased activity of the sympathetic nervous system. To study changes in regional cerebral blood flow (rCBF) related to the defense reaction, volunteers with snake phobia were investigated with positron emission tomography. The relative rCBF during phobogenic visual stimulation was increased in the secondary visual cortex but reduced in the hippocampus, orbitofrontal, prefrontal, temporopolar, and posterior cingulate cortex compared with that observed during neutral visual stimulation. The relative rCBF under aversive stimulation was intermediate between phobic and neutral stimulation. The rCBF patterns observed are suggested to represent a functional cerebral correlate to the visually elicited defense reaction and its associated emotions.
Collapse
Affiliation(s)
- G Wik
- Department of Psychiatry and Psychology, Karolinska Institute and Hospital, Stockholm, Sweden
| | | | | | | | | | | |
Collapse
|
23
|
|
24
|
Kabalka GW. Boron: Boranes in organic synthesis. J Organomet Chem 1987. [DOI: 10.1016/0022-328x(87)87185-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
25
|
Herscovitch P, Raichle ME, Kilbourn MR, Welch MJ. Positron emission tomographic measurement of cerebral blood flow and permeability-surface area product of water using [15O]water and [11C]butanol. J Cereb Blood Flow Metab 1987; 7:527-42. [PMID: 3498732 DOI: 10.1038/jcbfm.1987.102] [Citation(s) in RCA: 166] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have previously adapted Kety's tissue autoradiographic method for measuring regional CBF in laboratory animals to the measurement of CBF in humans with positron emission tomography (PET) and H2(15)O. Because this model assumes diffusion equilibrium between tissue and venous blood, the use of a diffusion-limited tracer, such as H2(15)O, may lead to an underestimation of CBF. We therefore validated the use of [11C]butanol as an alternative freely diffusible tracer for PET. We then used it in humans to determine the underestimation of CBF that occurs with H2(15)O, and thereby were able to calculate the extraction Ew and permeability-surface area product PSw of H2(15)O. Measurements of the permeability of rhesus monkey brain to [11C]butanol, obtained by means of an intracarotid injection, external detection technique, demonstrated that this tracer is freely diffusible up to a CBF of at least 170 ml/min-100 g. CBF measured in baboons with the PET autoradiographic method and [11C]butanol was then compared with CBF measured in the same animals with a standard residue detection method. An excellent correspondence was obtained between both of these measurements. Finally, paired PET measurements of CBF were made with both H2(15)O and [11C]butanol in 17 normal human subjects. Average global CBF was significantly greater when measured with [11C]butanol (53.1 ml/min-100 g) than with H2(15)O (44.4 ml/min-100 g). Average global Ew was 0.84 and global PSw was 104 ml/min-100 g. Regional measurements showed a linear relationship between local PSw and CBF, while Ew was relatively uniform throughout the brain. Simulations were used to determine the potential error associated with the use of an incorrect value for the brain-blood partition coefficient for [11C]butanol and to calculate the effect of tissue heterogeneity and errors in flow measurement on the calculation of PSw.
Collapse
Affiliation(s)
- P Herscovitch
- Department of Neurology and Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri
| | | | | | | |
Collapse
|
26
|
Kothari PJ, Finn RD, Kabalka GW, Vora MM, Boothe TE, Emran AM, Mohammadi M. Carbon-11 labeled dialkylketones: synthesis of 9-[11C]heptadecan-9-one. INTERNATIONAL JOURNAL OF RADIATION APPLICATIONS AND INSTRUMENTATION. PART A, APPLIED RADIATION AND ISOTOPES 1986; 37:471-3. [PMID: 3019947 DOI: 10.1016/0883-2889(86)90149-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
9-[11C]heptadecan-9-one was synthesized from di-n-octylthexylborane via cyanidation with K11CN. The rearrangement of the organoborane intermediate followed by alkaline oxidation produced the title compound in 55-60 min from the end of bombardment (EOB) in 50-70% overall yield. The reaction sequence is applicable for the synthesis of various dialkyl ketones.
Collapse
|
27
|
Kothari PJ, Finn RD, Kabalka GW, Vora MM, Boothe TE, Emran AM. Synthesis of nitrogen-13 labeled alkylamines via amination of organoboranes. INTERNATIONAL JOURNAL OF RADIATION APPLICATIONS AND INSTRUMENTATION. PART A, APPLIED RADIATION AND ISOTOPES 1986; 37:469-70. [PMID: 3019946 DOI: 10.1016/0883-2889(86)90148-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Organoboranes react with nitrogen-13 labeled ammonia to produce alkylamines in moderate yield. When 13N labeled ammonia was bubbled into a tetrahydrofuran solution containing 0.5M tridecylborane, 1-[13N]aminodecane was formed in 25-30 min from the end of bombardment (EOB) in 40-60% overall yield. 1-[13N]aminooctane and 1-[13N]aminohexane were also synthesized from appropriate organoboranes in similar yield.
Collapse
|