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Housh AB, Powell G, Scott S, Anstaett A, Gerheart A, Benoit M, Waller S, Powell A, Guthrie JM, Higgins B, Wilder SL, Schueller MJ, Ferrieri RA. Functional mutants of Azospirillum brasilense elicit beneficial physiological and metabolic responses in Zea mays contributing to increased host iron assimilation. ISME J 2021; 15:1505-1522. [PMID: 33408368 PMCID: PMC8115672 DOI: 10.1038/s41396-020-00866-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 10/28/2020] [Accepted: 12/03/2020] [Indexed: 01/29/2023]
Abstract
Iron (Fe), an essential element for plant growth, is abundant in soil but with low bioavailability. Thus, plants developed specialized mechanisms to sequester the element. Beneficial microbes have recently become a favored method to promote plant growth through increased uptake of essential micronutrients, like Fe, yet little is known of their mechanisms of action. Functional mutants of the epiphytic bacterium Azospirillum brasilense, a prolific grass-root colonizer, were used to examine mechanisms for promoting iron uptake in Zea mays. Mutants included HM053, FP10, and ipdC, which have varying capacities for biological nitrogen fixation and production of the plant hormone auxin. Using radioactive iron-59 tracing and inductively coupled plasma mass spectrometry, we documented significant differences in host uptake of Fe2+/3+ correlating with mutant biological function. Radioactive carbon-11, administered to plants as 11CO2, provided insights into shifts in host usage of 'new' carbon resources in the presence of these beneficial microbes. Of the mutants examined, HM053 exhibited the greatest influence on host Fe uptake with increased plant allocation of 11C-resources to roots where they were transformed and exuded as 11C-acidic substrates to aid in Fe-chelation, and increased C-11 partitioning into citric acid, nicotianamine and histidine to aid in the in situ translocation of Fe once assimilated.
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Affiliation(s)
- A B Housh
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- Chemistry Department, University of Missouri, Columbia, MO, 65211, USA
| | - G Powell
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - S Scott
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - A Anstaett
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- Department of Chemical Engineering, University of Missouri, Columbia, MO, 65211, USA
- Burns & McDonnell, Inc. 425 S, Woods Mill Rd., Chesterfield, MO, USA, 63017
| | - A Gerheart
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- Chemistry Department, University of Missouri, Columbia, MO, 65211, USA
- Idaho State Police 5255 S. 5th Ave, Pocatello, ID, 83204, USA
| | - M Benoit
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - S Waller
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- School of Natural Resources, University of Missouri, Columbia, MO, 65211, USA
| | - A Powell
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- School of Natural Resources, University of Missouri, Columbia, MO, 65211, USA
| | - J M Guthrie
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
| | - B Higgins
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
| | - S L Wilder
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
| | - M J Schueller
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- Chemistry Department, University of Missouri, Columbia, MO, 65211, USA
| | - R A Ferrieri
- Missouri Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA.
- Chemistry Department, University of Missouri, Columbia, MO, 65211, USA.
- Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO, 65211, USA.
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Gerasimov MR, Ferrieri RA, Schiffer WK, Logan J, Gatley SJ, Gifford AN, Alexoff DA, Marsteller DA, Shea C, Garza V, Carter P, King P, Ashby CR, Vitkun S, Dewey SL. Study of brain uptake and biodistribution of [11C]toluene in non-human primates and mice. Life Sci 2002; 70:2811-28. [PMID: 12269385 DOI: 10.1016/s0024-3205(02)01542-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [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
Inhalant abuse is a rapidly growing health problem particularly among adolescents. Yet we know little about the neural mechanisms underlying the abuse liability of inhalants, particularly when compared to other addictive drugs. Specifically, our understanding of the relationship between the regional brain phamacokinetics and features classically associated with drug reinforcement is lacking. Under the hypothesis that the abuse liability of toluene can be related to its pharmacokinetic properties and the pattern of regional brain uptake, we developed the methodology for radiolabeling and purifying [11C]toluene for use in PET studies. Here we report the regional brain distribution and kinetics of the widely abused solvent toluene in non-human primates and the whole body biodistribution in mice. To our knowledge, this is the first reported study of the in vivo brain pharmacokinetics of labeled toluene in non-human primates. Rapid uptake of radioactivity into striatal and frontal regions was followed by rapid clearance from the brain. Concurrent findings in rodents indicate similar radio-tracer kinetics, with excretion through kidneys and liver. Taken together, our data provides insight into pharmacokinetic features possibly associated with the abuse liability of toluene.
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Affiliation(s)
- M R Gerasimov
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
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Galynker I, Schlyer DJ, Dewey SL, Fowler JS, Logan J, Gatley SJ, MacGregor RR, Ferrieri RA, Holland MJ, Brodie J, Simon E, Wolf AP. Opioid receptor imaging and displacement studies with [6-O-[11C] methyl]buprenorphine in baboon brain. Nucl Med Biol 1996; 23:325-31. [PMID: 8782244 DOI: 10.1016/0969-8051(95)02087-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Buprenorphine (BPN) is a mixed opiate agonist-antagonist used as an analgesic and in the treatment of opiate addiction. We have used [6-O-[11C]methyl]buprenorphine ([11C]BPN) to measure the regional distribution in baboon brain, the test-retest stability of repeated studies in the same animal, the displacement of the labeled drug by naloxone in vivo, and the tissue distribution in mice. The regional distribution of radioactivity in baboon brain determined with PET was striatum > thalamus > cingulate gyrus > frontal cortex > parietal cortex > occipital cortex > cerebellum. This distribution corresponded to opiate receptor density and to previously published data (37). The tracer uptake in adult female baboons showed no significant variation in serial scans in the same baboon with no intervention in the same scanning session. HPLC analysis of baboon plasma showed the presence of labeled metabolites with 92% +/- 2.2% and 43% +/- 14.4% of the intact tracer remaining at 5 and 30 min, respectively. Naloxone, an opiate receptor antagonist, administered 30-40 min after tracer injection at a dose of 1.0 mg/kg i.v., reduced [11C]BPN binding in thalamus, striatum, cingulate gyrus, and frontal cortex to values 0.25 to 0.60 of that with no intervention. There were minimal (< 15%) effects on cerebellum. Naloxone treatment significantly reduced the slope of the Patlak plot in receptor-containing regions. These results demonstrate that [11C]BPN can be displaced by naloxone in vivo, and they affirm the feasibility of using this tracer and displacement methodology for short-term kinetics studies with PET. Mouse tissue distribution data were used to estimate the radiation dosimetry to humans. The critical organ was the small intestine, with a radiation dose estimate to humans of 117 nrad/mCi.
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Affiliation(s)
- I Galynker
- Beth Israel Hospital, New York, NY 10003, USA
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Ferrieri RA, Alexoff DL, Schlyer DJ, Wolf AP. Remote processing, delivery and injection of H2[15O] produced from a N2/H2 gas target using a simple and compact apparatus. Appl Radiat Isot 1994; 45:1149-54. [PMID: 7894394 DOI: 10.1016/0969-8043(94)90030-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We report here a simple apparatus for remote trapping and processing of H2[15O] produced from the N2/H2 target. The system performs a three step operation for H2[15O] delivery at the PET imaging facility which includes the following: (i) collecting the radiotracer in sterile water; (ii) adjusting preparation pH through removal of radiolytically produced ammonia, while at the same time adjusting solution isotonicity; and (iii) delivery of the radiotracer preparation to the injection syringe in a sterile and pyrogen-free form suitable for human studies. The processing apparatus is simple, can be remotely operated and fits inside a Capintec Dose Monitoring Chamber for direct measurement of accumulated radioactivity. Using this system, 300 mCi of H2[15O] (15 microA of 8 MeV D+ on target) is transferred from target through 120 m x 3.18 mm o.d. Impolene tubing to yield 100 mCi of H2[15O] which is isotonic, neutral and suitable for human studies. A remote hydraulically driven system for i.v. injection of the H2[15O] is also described. The device allows for direct measurement of syringe dose while filling, and for easy, as well as safe transport of the injection syringe assembly to the patient's bedside via a shielded delivery cart. This cart houses a hydraulic piston that allows the physician to "manually" inject the radiotracer without directly handling the syringe.
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Affiliation(s)
- R A Ferrieri
- Department of Chemistry, Brookhaven National Laboratory, Upton, NY 11973
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Ferrieri RA, Alexoff DL, Schlyer DJ, Wolf AP. A universal water target loading system with direct in-target liquid level sensing. Int J Rad Appl Instrum A 1992; 43:1485-91. [PMID: 1334955 DOI: 10.1016/0883-2889(92)90176-f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A reliable remote water target loading system has been designed and fabricated around the operation of a single pneumatic syringe dispenser that accesses one of two water reservoirs, filling one or more targets depending on the system configuration. For multiple radionuclide configuration, reservoirs are filled with 18O-enriched water for [18F]fluoride production, and natural abundance water for [13N]nitrate and [13N]nitrite production. When actuated, the system withdraws a calibrated volume of water from a selected reservoir, and automatically dispenses that charge through a short transfer line to the appropriate target. A second actuation then forces the dispenser to purge itself of residual water by dispensing a charge of helium gas through the same line thus completing the transfer of water to the target volume. Direct liquid level sensing inside the target, utilizing the specific resistance response of water, signals the operator that the target is loaded. For single radionuclide configuration, one or both reservoirs can be used with the same type of water, while dispensing is directed to a single target.
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Affiliation(s)
- R A Ferrieri
- Brookhaven National Laboratory, Department of Chemistry, Upton, NY 11973
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Dewey SL, Smith GS, Logan J, Brodie JD, Yu DW, Ferrieri RA, King PT, MacGregor RR, Martin TP, Wolf AP. GABAergic inhibition of endogenous dopamine release measured in vivo with 11C-raclopride and positron emission tomography. J Neurosci 1992; 12:3773-80. [PMID: 1357114 PMCID: PMC6575948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023] Open
Abstract
Extensive neuroanatomical, neurophysiological, and behavioral evidence demonstrates that GABAergic neurons inhibit endogenous dopamine release in the mammalian corpus striatum. Positron emission tomography (PET) studies in adult female baboons, using the dopamine D2-specific radiotracer 11C-raclopride, were undertaken to assess the utility of this imaging technique for measuring these dynamic interactions in vivo. 11C-raclopride binding was imaged prior to and following the administration of either gamma-vinyl-GABA (GVG), a specific suicide inhibitor of the GABA-catabolizing enzyme GABA transaminase, or lorazepam, a clinically prescribed benzodiazepine agonist. Striatal 11C-raclopride binding increased following both GVG and lorazepam administration. This increase exceeded the test/retest variability of 11C-raclopride binding observed in the same animals. These findings confirm that changes in endogenous dopamine concentrations resulting from drug-induced potentiation of GABAergic transmission can be measured with PET and 11C-raclopride. Finally, this new strategy for noninvasively evaluating the functional integrity of neurophysiologically linked transmitter systems with PET supports its use as an approach for assessing the multiple mechanisms of drug action and their consequences in the human brain.
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Affiliation(s)
- S L Dewey
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973
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