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1.
Shinichiro Hirose Yukiko Umetani Misato Amitani Rie Hosoi Sotaro Momosaki Jun Hatazawa Antony Gee Osamu Inoue 《Neuroscience letters》2007
The effect of inhibition of glial metabolism by infusion of fluorocitrate (FC, 1 nmol/μl, 2 μl) into the right striatum of the rat brain on the glucose metabolism was studied. Significant increases in [18F]fluorodeoxyglucose ([18F]FDG) uptake (45 min) in the right cerebral cortex and striatum were observed 4 h after the infusion of FC, both as determined by the tissue dissection method and autoradiography. No significant increase in the initial uptake of [18F]FDG (1 min) was seen in the striatum. Pretreatment with dizocilpine (MK-801), an N-methyl-d-aspartate (NMDA) receptor antagonist, reduced [18F]FDG uptake in not only FC infused hemisphere but also in the contralateral hemisphere (saline-infused side). The radioactivity concentrations in plasma at 1, 5 and 45 min after the [18F]FDG injection were not altered by MK-801. This effect of MK-801 on glucose metabolism observed in the rat brain infused with FC was different from previous reports which indicated an increase in glucose metabolism in some areas of normal rat brain. In addition, the enhancement of glucose metabolism in the striatum induced by FC was almost completely abolished by pretreatment with MK-801. In the cerebral cortex, the relative ratio of radioactivity concentration in the right hemisphere to that in the left hemisphere still remained 1.37 (tissue dissection method) or 1.55 (autoradiography), which indicated that MK-801 partially blocked the effect of FC of enhancing glucose metabolism in this region. These results indicate an important role of NMDA-mediated signal transmission on the increase of glucose utilization induced by inhibition of glial metabolism. 相似文献
2.
Jun Hatazawa Hiroshi Itoh Eku Shimosegawa Iwao Kanno Matsutaroh Murakami Shuichi Miura Hidehiro Iida Toshio Okudera Atsushi Inugami Toshihide Ogawa Hideaki Fujita Yuichi Satoh Ken Nagata Yutaka Hirata Kazuo Uemura 《Annals of nuclear medicine》1994,8(3):213-217
We studied the brain uptake of amino acid in a patient with acute cerebral infarction with L-[2-(F-18)] fluorophenylalanine and positron emission tomography. The increased accumulation of the ligand was specifically found in the peri-infarct area where oxygen metabolism was still maintained but decreased later in the 72-day follow-up period. The kinetic analysis revealed that increased accumulation was not due to increased transport from the blood to the brain but to delayed washout from the brain to the blood. Although the mechanism is still unknown, abnormally high accumulation of L-[F-18]fluorophenylalanine may predict delayed neuronal changes after ischemic insults of the brain. 相似文献
3.
Motonobu Kameyama Kiichi Ishiwata Yuji Tsurumi Jun Itoh Kiyotaka Sato Ryuichi Katakura Takashi Yoshimoto Jun Hatazawa Masatoshi Ito Tatsuo Ido 《Journal of neuro-oncology》1995,23(1):53-61
Summary Positron emission tomography was used to investigate the metabolism of nucleic acids by18F-fluoro-2-deoxyuridine (18F-FUdR) in 22 patients with gliomas. Sixteen cases of high grade glioma clearly demonstrated a region of high activity with a differential absorption rate (DAR) of 0.64 ± 0.34. Six cases of low grade glioma failed to reveal a positive image of the tumor and the DAR in tumor was 0.21 ± 0.042 (p < 0.01). This PET-18F-FUdR study succeeded in differentiating high and low grade gliomas from the view point of nucleic acid metabolism. 相似文献
4.
Subependymoma of the septum pellucidum: Characterization by PET 总被引:1,自引:0,他引:1
Mineura Katsuyoshi Shioya Hitoshi Kowada Masayoshi Ogawa Toshihide Hatazawa Jun Uemura Kazuo 《Journal of neuro-oncology》1997,32(2):143-147
We report the evaluation of a subependymoma of the septum pellucidum by positron emission tomography (PET) with analysis of 18F-fluorodeoxyglucose (FDG)kinetics. The tumor showed exceedingly low rates of glucose metabolism (rCMRG1) and kinetic constants (K1, K2, and K3). This hypometabolism indicates low cellular density and slow growth. 相似文献
5.
M Itoh J Hatazawa H Miyazawa H Matsui K Meguro K Yanai K Kubota S Watanuki T Ido T Matsuzawa 《Gerontology》1990,36(1):43-48
Cerebral blood flow and oxygen metabolism in aged normal subjects were measured with positron emission tomography and their relationship with brain atrophy was evaluated. Brain atrophy progressed in a linear fashion during aging while cerebral blood flow and oxygen metabolism were well preserved. The finding suggests that brain atrophy is an aging process less dependent on cerebral blood flow and metabolism over the course of normal aging. 相似文献
6.
Hasegawa S Kusuoka H Maruyama K Nishimura T Hori M Hatazawa J 《Journal of the American College of Cardiology》2004,43(2):224-233
OBJECTIVES: The aim of this study was to elucidate whether the response of idiopathic dilated cardiomyopathy (DCM) patients to beta-blockers can be predicted by positron emission tomography with fluorine-18 fluoro-2-deoxyglucose (FDG-PET). BACKGROUND: Patients with DCM often have a poor prognosis, and it is important to predict their response to beta-blocker therapy, which may be effective in DCM. However, no accurate methods of predicting their response have been available. METHOD: In 22 DCM patients with reduced left ventricular (LV) systolic function, FDG-PET was performed. Uptake in the LV after glucose loading was evaluated based on the average global percent uptake of the injected dose (G%ID) and the coefficient of variance (CV) in 24 segments of the LV. Uptake during fasting was evaluated semiquantitatively on the basis of the total uptake score. The beta-blocker was administered, and LV function was monitored by echocardiography. The histologic findings were assessed in the 18 patients who underwent endomyocardial biopsy. RESULTS: The beta-blocker was effective in the majority of patients whose G%ID after glucose loading was >0.7%, and the sensitivity and specificity of G%ID as a predictor of beta-blocker efficacy were 83.3% and 90.0%, respectively. Percent CV did not predict efficacy. Four groups, defined on the basis of the FDG uptake score during fasting and G%ID after glucose loading, had distinctive histologic findings and outcomes. CONCLUSIONS: It has been shown that FDG-PET is a good predictor for the effectiveness of beta-blockers. 相似文献
7.
Sadahiro Naka Toshimitsu Watanabe Yasukazu Kanai Tadashi Watabe Mitsuaki Tatsumi Hiroki Kato Eku Shimosegawa Jun Hatazawa 《Nuclear Medicine and Molecular Imaging》2022,56(2):86
Purpose4-Borono-2-[18F]fluoro-l-phenylalanine ([18F]FBPA) synthesized with [18F]F2, produced using the 18O(p, n)18F reaction, has been reported for increasing radioactivity. However, a dedicated system and complex procedure is required to reuse the costly [18O]O2 gas; also, the use of [18F]F2 as a labeling agent reduces the labeling rate and radiochemical purity. We developed a stable and practical method for [18F]FBPA synthesis by combining [18F]F2, produced using a [18O]O2 single-use system, and a [18F]CH3COOF labeling agent.MethodsThe produced [18F]F2 was optimized, and then [18F]FBPA was synthesized. For passivation of the target box, 0.5% F2 was pre-irradiated in argon. Gaseous products were discarded; the target box was filled with [18O]O2 gas, and then irradiated (first irradiation). Then, the [18O]O2 gas was discarded, 0.05–0.08% F2 in argon was fed into the target box, and it was again irradiated (second irradiation). The [18F]F2 obtained after this was passed through a CH3COONa column, converting it into the [18F]CH3COOF labeling agent, which was then used for [18F]FBPA synthesis.ResultsThe mean amount of as-obtained [18F]F2 was 55.0 ± 3.3 GBq and that of as-obtained [18F]CH3COOF was 21.6 ± 1.4 GBq after the bombardment. The radioactivity and the radiochemical yield based on [18F]F2 of [18F]FBPA were 4.72 ± 0.34 GBq and 12.2 ± 0.1%, respectively. The radiochemical purity and molar activity were 99.3 ± 0.1% and 231 ± 22 GBq/mmol, respectively.ConclusionWe developed a method for [18F]FBPA production, which is more stable and practical compared with the method using [18O]O2 gas-recycling and [18F]F2 labeling agent. 相似文献
8.
Vascular and metabolic reserve in a case of hypoplasia of bilateral internal carotid arteries] 总被引:3,自引:0,他引:3
H Kato K Nagata S Kawamura A Suzuki M Sato Y Mito H Maruya J Hatazawa Y Watahiki Y Sato Y Hirata H Utumi 《Clinical neurology》2000,40(11):1096-1100
We report a 64-year-old right-handed man who presented with a hypoplasia of bilateral internal carotid arteries (ICAs). The patient complained of a vertigo and was diagnosed as having a benign paroxysmal positional vertigo. Upon neurological examination, he was completely free from neurological deficits. MR angiogram revealed an occlusion of both ICAs. On conventional angiogram, the right ICA was occluded about 3 cm distal from its origin, and the left ICA was occluded at the precavernous portion. There was an abundant collateral blood flow to the frontal, temporal and parietal lobes through the posterior communicating arteries. Both carotid canals were hypoplastic on 3D-CT. The patient was then diagnosed as having a hypoplasia of both ICAs. Using a positron emission tomography (PET), cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO2), oxygen extraction fraction (OEF), and vascular transit time (VTT) were measured during resting state, and the vascular reactivities to carbon dioxide inhalation (VRCO2), and to the intravenous administration of Acetazolamide (VRACZ) were also evaluated. There was no global or focal reduction in CBF and VTT was within normal limit, whereas a global reduction of CMRO2 caused mild decrease in OEF. Moreover, VRACZ was significantly decreased and an intracerebral steal phenomenon was observed in the parietal cortical areas, whereas VRCO2 was preserved. The discrepancy between VRACZ and VRCO2 observed could be related to the differences in the mechanisms underlying the vasodilating effects of carbon dioxide and ACZ. 相似文献
9.
A 38-year-old woman with Chiari I malformation presented with spinal cord edema preceding syringomyelia manifesting as a 5-month history of nuchal pain and numbness of the upper extremities. Magnetic resonance imaging showed spinal cord edema, a poorly defined syrinx at the C-2 to T-2 levels, and distorted cerebellar tonsils. Computed tomography revealed cerebrospinal fluid (CSF) density in the center of spinal cord edema, and positron emission tomography revealed no uptake of L-[methyl-11C]methionine, indicating a non-neoplastic lesion. Craniocervical decompression achieved excellent clinical and neuroradiological outcomes. The success of surgical treatment supports the theory that patients with Chiari I malformation have increased transmural flow of CSF, causing spinal cord edema that progresses to syringomyelia. Early treatment of patients with spinal cord edema is indicated to prevent permanent spinal cord injury due to progressive syringomyelia. 相似文献
10.
Volume expansion associated with brain infarction occurs in perfusion-diffusion mismatch of magnetic resonance imaging. We aimed at elucidating the metabolic impairment of this phenomenon with (15)O positron emission tomography and perfusion and diffusion magnetic resonance imaging. Eleven patients with acute unilateral embolic occlusion of the internal carotid or middle cerebral artery were studied within 6 hours of onset. Regional cerebral blood flow and cerebral metabolic rate of oxygen (CMRO(2)) were compared with those in the contralateral cerebral hemisphere. The relative apparent diffusion coefficient of water was estimated as a marker of cytotoxic edema. Relative cerebral blood flow and relative CMRO(2) in an evolving infarct (normal diffusion initially, but abnormal on day 3) were significantly (p < 0.05) less than those in the periinfarct area (normal diffusion initially and on day 3). The relative apparent diffusion coefficient between the evolving infarct and periinfarct showed no significant difference. These findings indicated that the initial 3-day volume expansion of an embolic brain infarction was associated with disturbed CMRD(2) but not with cytotoxic edema as early as 6 hours after onset. The "metabolic penumbra" defined as normal water diffusion with depressed CMRO(2) is a target to reduce the volume expansion of brain infarction. 相似文献