The labelling synthesis of ethyl nitro2-(11)Cacetate, a synthetic intermediate feasible for (11)C-labelled PET tracers, by C-carboxylation of (11)CMeNO(2) with 1-ethoxycarbonylbenzotriazole, and its ...simple application are presented.
It has been demonstrated in vitro that the dopamine D(2) receptor has 2 interconvertible affinity states for endogenous dopamine, referred to as the high- and the low-affinity states. ...(11)C-(R)-2-CH(3)O-N-n-propylnorapomorphine ((11)C-MNPA) is a new agonist radioligand for in vivo imaging of the high-affinity state of dopamine D(2) receptors using PET. In the present study, the kinetics of (11)C-MNPA were examined for the first time, to our knowledge, in the human brain and analyzed using quantitative approaches with or without an arterial input function.
A 90-min dynamic PET scan was obtained for 10 healthy men after an intravenous injection of (11)C-MNPA. The binding potential (BP(ND)) was calculated using the indirect kinetic method, a kinetic compartment analysis with a metabolite-corrected arterial input function. BP(ND) was also calculated by the simplified reference tissue model (SRTM) and transient equilibrium methods, both with the cerebellum as the reference brain region. The results of the quantitative methods were compared in a cross-validation approach.
The highest regional radioactivity was observed in the putamen. BP(ND) values obtained by kinetic analysis were 0.82 +/- 0.09, 0.59 +/- 0.11, and 0.28 +/- 0.06, respectively, in the putamen, caudate, and thalamus. BP(ND) values obtained by the SRTM and transient equilibrium methods were in good agreement with those obtained by the indirect kinetic method (r = 0.98 and r = 0.93, respectively). For all quantification methods, the BP(ND) values based on data acquired from 0 to 60 min were in good agreement with those based on data acquired from 0 to 90 min (r = 0.90-0.99).
The regional distribution of (11)C-MNPA binding was in good agreement with previous PET studies of dopamine D(2) receptors in the human brain using antagonist radioligands. The results support routine use of the SRTM and transient equilibrium methods, that is, methods that do not require an arterial input function and need a scan time of only about 60 min. (11)C-MNPA should thus be useful for clinical research on the pathophysiology of neuropsychiatric disorders and estimation of dopamine D(2) receptor occupancy by dopaminergic drugs.
Purpose: The development of the novel carbon ion radiotherapy (CIRT) in the treatment of refractory cancers has resulted in the need
for a way to accurately evaluate patient prognosis. We evaluated ...whether l -methyl- 11 C-methionine (MET) uptake and its change after CIRT were the early survival predictors in patients with unresectable bone
and soft tissue sarcomas.
Experimental Design: MET positron emission tomography was prospectively performed in 62 patients with unresectable bone and soft tissue sarcomas
before and within 1 month after CIRT. Tumor MET uptake was measured with the semiquantitative tumor:nontumor ratio (T/N ratio).
The MET uptake in the tumor and relevant clinical parameters were entered into univariate and multivariate survival analysis.
Results: The overall median survival time was 20 months. Patients with a baseline T/N ratio of ≤6 had a significant better survival
than patients with a baseline T/N ratio >6 (2-year survival rate: 69.4% versus 32.3%; P = 0.01). Patients with a post-CIRT ratio of ≤4.4 had a better survival than that with a post-CIRT ratio >4.4 (2-year survival
rate: 63.7% versus 41.3%; P = 0.01). A significant higher survival rate was observed in patients with post-therapeutic MET uptake change of >30% than
patients in lower change group (2-year survival rate: 74.6% versus 41.6%; P = 0.049). The multivariate analysis showed that both baseline and post-CIRT T/N ratio were statistically significant independent
predictors of patient survival. Tumors with larger T/N ratio had a significantly poorer prognosis.
Conclusions: MET uptake as measured by either baseline or post-CIRT T/N ratio was an independent predictor of survival in patients with
bone and soft tissue sarcomas treated by carbon ion radiotherapy, whereas post-therapeutic MET uptake change might have potential
value for the same purpose.
The lateral water movement in the intact stem of a transpiring soybean plant was analyzed quantitatively by a real-time measurement system utilizing labeled water, H₂¹⁵O and gamma ray detectors. A ...large volume of water escaping from xylem vessels during its transport was detected. The escape of water was not influenced by evaporation from the stem surface or mass flow in the sieve tubes. It was assumed that the total amount of water transported through xylem vessels was kept almost completely constant along the internode. As a result, most of the escaped water was found to re-enter the xylem vessels, i.e. water exchange occurred. The analysis of radiographs of tritiated water suggested that the self-diffusion effect of water was strong for lateral water movement, although another driving force besides thermal motion was included in the process, and that the process was also affected by the water permeability of the plasma membrane. An analysis based on a mathematical model showed that the net volume of water which escaped from xylem vessels was not dependent on the transpiration rate of the plant.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract High-affinity iodine- and ethyl-C-5 substituted analogs of 4-hydroxy-3-(3-11 Cmethoxyphenyl)-2(1 H )-quinolone (11 C4HQ) were synthesized as new positron emission tomography radioligands for ...the glycine-binding sites of the N- methyl- d -aspartate (NMDA) ion channel. Although both radioligands showed high in vitro specific binding to rat brain slices, their binding characteristics were quite different from each other. 5-Ethyl-11 C4HQ (5Et-11 C4HQ) showed higher in vitro binding in the forebrain regions than in the cerebellum, bindings that were strongly inhibited by both glycine-site agonists and antagonists. In contrast, 5-iodo-11 C4HQ (5I-11 C4HQ) showed a homogeneous in vitro binding throughout the brain, which was inhibited by antagonists but not by agonists. This difference in in vitro binding between 5Et-11 C4HQ and 5I-11 C4HQ was quite similar to that previously observed between 11 CL-703,717 and 11 C4HQ, both glycine-site antagonists. In vivo brain uptakes of these11 C-labeled 4-hydroxyquinolones were examined in mice. Initial brain uptakes of 5Et- and 5I-11 C4HQ at 1 min after intravenous injections were comparable to that of 11 C4HQ, but they were 1.3–2.1 times higher than that of 11 CL-703,717. The treatment with an anticoagulant, warfarin, only slightly increased the initial uptakes of 11 C4HQ and 5Et-11 C4HQ in contrast to 11 CL-703,717. The in vivo regional brain distributions were slightly different between the two radioligands. Pretreatment with nonradioactive ligand (2 mg/kg) slightly inhibited the binding of 5Et-11 C4HQ (16–36% inhibition) but not that of 5I-11 C4HQ. In this study, it was found that a small structural change in 11 C4HQ resulted in a major change in binding characteristics and distributions, suggesting the existence of two binding sites for 11 C4-hydroxyquinolones on the NMDA ion channel — agonist-sensitive and agonist-insensitive (or antagonist-preferring) sites.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The U.S.-Japan Structural Impediments Initiative (SII) included six different areas. Although negotiated simultaneously, the distributive results of each area were quite different. Previous studies ...have attempted to explain this outcome by comparing each area’s internal conditions (e.g., the degree of participation expansion in the Japanese political process, the similarity of the perceptions of two government officials regarding the problem involved). However, this research design is inappropriate for an omnibus negotiation like SII. For a comparison to be valid, the outcomes of each area have to be independent. If there is a cross-area barter, the outcome of area A cannot be explained only by the internal condition of area A. Using primary sources and analytical models, this paper demonstrates the effect of cross-area issue linkage in SII, and thereby overthrows conventional explanation on why U.S. pressure succeeded in some areas but not others. The first part elaborates two spatial models of multi-issue bargaining between two governments, and suggests how the outcome of international negotiation is affected by whether or not participating governments can strike cross-area barters. The second part empirically shows when the U.S. and Japanese governments were ready to make such barter deals. At first, the level of negotiation was sub-cabinet and both governments suffered from interagency conflicts, leaving no room for sacrificing one agency’s issues for the sake of another’s. This situation changed when top-level policy makers took direct command in both countries. The top policy makers in the U.S. allowed their Japanese counterparts to choose across areas, on the condition that the package as a whole is significant. The third part quantitatively evaluates newly declassified records of the negotiation, and shows the timeline change in the Japanese responses to the U.S. requests. This clearly illustrates the reversal in the pattern of Japanese concession when the top policy makers intervened. At first, Japanese concession was concentrated in keiretsu and exclusionary business practice areas, where the potential targets of U.S. retaliation (export sector and large business) were most affected by U.S. demands. After the change in the level of decision making, significant concessions were made in the other areas, while the draft of keiretsu and business practices was left virtually untouched. This observed tendency fits in with the prediction of the models; however, no major preceding hypothesis on SII can explain it. Theoretical research on bargaining has shown very clearly that issue linkages can completely change the bargaining outcome. However, empirical case studies of issue linkages in specific negotiations have seldom matched the clarity, owing to the difficulty in obtaining direct evidence of highly political barters, which involve intense conflict between interest groups, bureaucratic agencies, and politicians. By compensating the lack of direct evidence by theoretical models, this paper adds one clear example and demonstrates a method to do so.
In supporting the prevention of global warming, highly energy efficient cold/hot water-saving equipment has been developed and it has been increasingly introduced in houses. Especially, when it comes ...to the hot-water supply equipment in Japan, which takes up 30% of total domestic energy consumption per household, cold/hot-water saving with single-lever faucets, which very much relies on how individuals use such faucets, is put to the test. The purpose of this study is to propose a method for using such faucets and the necessity of energy conservation to be considered in product development. To be more specific, this paper discussed the following three points: (1) Identify the operating position of a single lever by season, (2) Identify levels of understanding about the operating position of a single lever, (3) Identify the operating position of a single lever when operated by residents in each season and levels of residents' understanding.
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