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1,085 results on '"Yonekura, Y."'

103. Effects of hyperglycemia on FDG uptake in human brain and glioma

Author

Ishizu K, Nishizawa S, Yonekura Y, Norihiro Sadato, Magata Y, Tamaki N, Tsuchida T, Okazawa H, Miyatake S, and Ishikawa M

Subjects
Adult, Blood Glucose, Male, Brain Neoplasms, Brain, Glioma, Deoxyglucose, Middle Aged, Glucose, Fluorodeoxyglucose F18, Humans, Female, Aged, Tomography, Emission-Computed
Abstract

This study evaluates the effects of hyperglycemia on fluorodeoxyglucose (FDG) uptake in the human brain and in brain tumors.We performed glucose loading during FDG PET studies in nine patients with brain tumors (eight gliomas and one brain metastasis) and one with resected glioma. Two FDG PET scans were obtained in all cases within 1 wk in a control state and with glucose loading by intravenous infusion of 10% glucose solution. Serial arterial blood sampling was performed in all cases to obtain fractional uptake of FDG normalized by the plasma integral uptake of radioactivity (FU).In all nine patients with brain tumors, the tumor was depicted more clearly with glucose loading than in the control state. Glucose loading decreased FU in the cerebral cortex (54.2% +/- 13.8%) nearly in inverse proportion to the plasma glucose level, while the tumors showed a decrease (42.5% +/- 15.6%), resulting in an increased tumor-to-cortex ratio by 26.0% +/- 5.7%. Fractional uptake in the cerebellum, white matter and the edematous area also decreased by glucose loading (53.9% +/- 13.2%, 49.6% +/- 10.3% and 34.9% +/- 9.6%, respectively).These results demonstrate the different effects of hyperglycemia on normal brain tissue and on tumor, suggesting that glucose loading may be a valuable adjunct to FDG PET to enhance detection of recurrent or residual brain tumors.

Published
1994

104. SPECT images of technetium-99m-ethyl cysteinate dimer in cerebrovascular diseases: comparison with other cerebral perfusion tracers and PET

Author

Tsuchida T, Nishizawa S, Yonekura Y, Norihiro Sadato, Iwasaki Y, Fujita T, Matoba N, Magata Y, Tamaki N, and Konishi J

Subjects
Adult, Male, Tomography, Emission-Computed, Single-Photon, Amphetamines, Brain, Contrast Media, Cerebral Infarction, Organotechnetium Compounds, Middle Aged, Iofetamine, Iodine Radioisotopes, Technetium Tc 99m Exametazime, Cerebrovascular Circulation, Oximes, Humans, Female, Cysteine, Tomography, Emission-Computed
Abstract

To assess the clinical role of 99mTc-ethyl cysteinate dimer (ECD) as a cerebral perfusion tracer, 10 patients with unilateral cerebral infarction were studied.ECD SPECT images were compared with IMP and/or HMPAO SPECT in nine patients, seven in chronic phases and two in subacute phases. Five of these patients and one additional patient with chronic infarction received PET imaging in order to compare ECD distribution with quantitative regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO2) images.In patients with chronic cerebral infarction, regression analysis showed excellent correlation between ECD and IMP in the uptake ratio of lesions-to-nonaffected cortices (r = 0.91). In two cases of subacute infarction, decreased uptake of ECD was observed in the area of "luxury perfusion," which showed elevated or preserved rCBF with diminished rCMRO2. On visual analysis, ECD image contrast was less prominent compared to that of IMP, but contrast was better than that of HMPAO.ECD uptake showed a curvilinear relationship against rCBF, suggesting flow-limited uptake in a high flow range. ECD is a clinically useful cerebral perfusion tracer with distinct characteristics when compared with other available agents.

Published
1994

105. Photon dominated regions in NGC 3603

Author

Röllig, M., primary, Kramer, C., additional, Rajbahak, C., additional, Minamidani, T., additional, Sun, K., additional, Simon, R., additional, Ossenkopf, V., additional, Cubick, M., additional, Hitschfeld, M., additional, Aravena, M., additional, Bensch, F., additional, Bertoldi, F., additional, Bronfman, L., additional, Fujishita, M., additional, Fukui, Y., additional, Graf, U. U., additional, Honingh, N., additional, Ito, S., additional, Jakob, H., additional, Jacobs, K., additional, Klein, U., additional, Koo, B.-C., additional, May, J., additional, Miller, M., additional, Miyamoto, Y., additional, Mizuno, N., additional, Onishi, T., additional, Park, Y.-S., additional, Pineda, J., additional, Rabanus, D., additional, Sasago, H., additional, Schieder, R., additional, Stutzki, J., additional, Yamamoto, H., additional, and Yonekura, Y., additional

Published
2010
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106. ChemInform Abstract: Synthesis and Characterization of Radioiodinated (S)-5-Iodonicotine: A New Ligand for Potential Imaging of Brain Nicotinic Cholinergic Receptors by Single Photon Emission Computed Tomography.

Author

SAJI, H., primary, WATANABE, A., additional, MAGATA, Y., additional, OHMOMO, Y., additional, KIYONO, Y., additional, YAMADA, Y., additional, IIDA, Y., additional, YONEKURA, Y., additional, KONISHI, J., additional, and YOKOYAMA, A., additional

Published
2010
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109. PET and the autoradiographic method with continuous inhalation of oxygen-15-gas: theoretical analysis and comparison with conventional steady-state methods

Author

Norihiro Sadato, Yonekura Y, Senda M, Iwasaki Y, Matoba N, Tamaki N, Sasayama S, Magata Y, and Konishi J

Subjects
Brain Diseases, Oxygen Consumption, Oxygen Radioisotopes, Cerebrovascular Circulation, Administration, Inhalation, Animals, Autoradiography, Brain, Humans, Middle Aged, Aged, Tomography, Emission-Computed
Abstract

The steady-state method using 15O gas inhalation and positron emission tomography (PET) is a simple and practical way of imaging cerebral blood flow (CBF) and oxygen metabolism. Several disadvantages do exist, however, including prolonged examination time, requirement of steady-state and a large tissue heterogeneity effect. To avoid the drawbacks of the steady-state method but to preserve its simplicity, we applied the PET/autoradiographic method to the build-up phase during the continuous inhalation of 15O-gas with intermittent arterial sampling. A simulation study was performed to determine the optimal scanning period, evaluate the delay and dispersion effect of the input function and estimate the tissue heterogeneity effect. To assess the clinical feasibility of the proposed technique for the study of oxygen metabolism, sequential measurements with this method and the conventional steady-state method were performed in eight patients. The simulation study showed that a 5-min scan started 3 min after the commencement of 15O-gas inhalation was optimal. With this method, the delay and dispersion effect on CBF was the same as that of the conventional steady-state method, but the tissue heterogeneity effect was reduced. In eight patients, CBF values calculated by this method showed time dependency and were slightly higher than those obtained by the steady-state method. The oxygen extraction fraction showed no significant time dependency and was well correlated with that obtained by the steady-state method. We conclude that the proposed method is a simple and acceptable alternative to the conventional steady-state method.

Published
1993

110. 99mTc-HMPAO SPECT in the brain death--a case report

Author

Tsuchida T, Norihiro Sadato, Nishizawa S, Matoba N, Fujita T, Tamaki N, Konishi J, Tamai S, Shingu K, and Yonekura Y

Subjects
Male, Tomography, Emission-Computed, Single-Photon, Brain Death, Technetium Tc 99m Exametazime, Cerebrovascular Circulation, Oximes, Humans, Organotechnetium Compounds, Aged
Abstract

Brain single photon emission computed tomography (SPECT) with 99mTc-d,l-hexamethyl-propyleneamine oxime (HMPAO) was performed twice in a 78-year-old man clinically diagnosed as brain death according to the standard criteria of the Japanese Ministry of Welfare. The first brain SPECT demonstrated the tracer accumulation in the brain, indicating preserved cerebral blood flow. The second brain SPECT performed 3 days later revealed cessation of the blood flow. In patients with preserved cerebral blood flow, the diagnosis of brain death cannot be made, even if they meet the existing criteria, because previous report noted the recovery in some of those patients. Brain perfusion SPECT plays an important role as a confirmatory test for the diagnosis of the brain death.

Published
1993

112. $^\mathsf{{12}}$CO 4–3 and [CI] 1–0 at the centers of NGC 4945 and Circinus

Author

Hitschfeld, M., primary, Aravena, M., additional, Kramer, C., additional, Bertoldi, F., additional, Stutzki, J., additional, Bensch, F., additional, Bronfman, L., additional, Cubick, M., additional, Fujishita, M., additional, Fukui, Y., additional, Graf, U. U., additional, Honingh, N., additional, Ito, S., additional, Jakob, H., additional, Jacobs, K., additional, Klein, U., additional, Koo, B.-C., additional, May, J., additional, Miller, M., additional, Miyamoto, Y., additional, Mizuno, N., additional, Onishi, T., additional, Park, Y.-S., additional, Pineda, J. L., additional, Rabanus, D., additional, Röllig, M., additional, Sasago, H., additional, Schieder, R., additional, Simon, R., additional, Sun, K., additional, Volgenau, N., additional, Yamamoto, H., additional, and Yonekura, Y., additional

Published
2007
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113. Clumpy photon-dominated regions in Carina

Author

Kramer, C., primary, Cubick, M., additional, Röllig, M., additional, Sun, K., additional, Yonekura, Y., additional, Aravena, M., additional, Bensch, F., additional, Bertoldi, F., additional, Bronfman, L., additional, Fujishita, M., additional, Fukui, Y., additional, Graf, U. U., additional, Hitschfeld, M., additional, Honingh, N., additional, Ito, S., additional, Jakob, H., additional, Jacobs, K., additional, Klein, U., additional, Koo, B.-C., additional, May, J., additional, Miller, M., additional, Miyamoto, Y., additional, Mizuno, N., additional, Onishi, T., additional, Park, Y.-S., additional, Pineda, J. L., additional, Rabanus, D., additional, Sasago, H., additional, Schieder, R., additional, Simon, R., additional, Stutzki, J., additional, Volgenau, N., additional, and Yamamoto, H., additional

Published
2007
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114. UP-03.55

Author

Oyama, N., primary, Kaneda, T., additional, Nakai, M., additional, Shioyama, N., additional, Matsuta, Y., additional, Miwa, Y., additional, Yokoyama, O., additional, Okazawa, H., additional, Fujibayashi, Y., additional, and Yonekura, Y., additional

Published
2006
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115. Molecular Loops in the Galactic Center: Evidence for Magnetic Flotation

Author

Fukui, Y., primary, Yamamoto, H., additional, Fujishita, M., additional, Kudo, N., additional, Torii, K., additional, Nozawa, S., additional, Takahashi, K., additional, Matsumoto, R., additional, Machida, M., additional, Kawamura, A., additional, Yonekura, Y., additional, Mizuno, N., additional, Onishi, T., additional, and Mizuno, A., additional

Published
2006
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116. Molecular loops in the Galactic centre; evidence for magnetic floatation accelerating molecular gas

Author

Yamamoto, H., primary, Fukui, Y., additional, Fujishita, M., additional, Torii, K., additional, Kudo, N., additional, Nozawa, S., additional, Takahashi, K., additional, Matsumoto, R., additional, Machida, M., additional, Kawamura, A., additional, Yonekura, Y., additional, Mizuno, N., additional, Onishi, T., additional, and Mizuno, A., additional

Published
2006
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124. Clumpy photon-dominated regions in Carina

Author

Kramer, C., Cubick, M., Röllig, M., Sun, K., Yonekura, Y., Aravena, M., Bensch, F., Bertoldi, F., Bronfman, L., Fujishita, M., Fukui, Y., Graf, U. U., Hitschfeld, M., Honingh, N., Ito, S., Jakob, H., Jacobs, K., Klein, U., Koo, B.-C., May, J., Miller, M., Miyamoto, Y., Mizuno, N., Onishi, T., Park, Y.-S., Pineda, J. L., Rabanus, D., Sasago, H., Schieder, R., Simon, R., Stutzki, J., Volgenau, N., Yamamoto, H., Kramer, C., Cubick, M., Röllig, M., Sun, K., Yonekura, Y., Aravena, M., Bensch, F., Bertoldi, F., Bronfman, L., Fujishita, M., Fukui, Y., Graf, U. U., Hitschfeld, M., Honingh, N., Ito, S., Jakob, H., Jacobs, K., Klein, U., Koo, B.-C., May, J., Miller, M., Miyamoto, Y., Mizuno, N., Onishi, T., Park, Y.-S., Pineda, J. L., Rabanus, D., Sasago, H., Schieder, R., Simon, R., Stutzki, J., Volgenau, N., and Yamamoto, H.

Abstract

Context.The Carina region is an excellent astrophysical laboratory for studying the feedback mechanisms of newly born, very massive stars within their natal giant molecular clouds (GMCs) at only 2.35 kpc distance.

Published
2008
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130. THE JET AND ARC MOLECULAR CLOUDS TOWARD WESTERLUND 2, RCW 49, AND HESS J1023–575; 12CO AND 13CO (J = 2-1 and J = 1-0) OBSERVATIONS WITH NANTEN2 AND MOPRA TELESCOPE.

Author

Furukawa, N., Ohama, A., Fukuda, T., Torii, K., Hayakawa, T., Sano, H., Okuda, T., Yamamoto, H., Moribe, N., Mizuno, A., Maezawa, H., Onishi, T., Kawamura, A., Mizuno, N., Dawson, J. R., Dame, T. M., Yonekura, Y., Aharonian, F., Wilhelmi, E. de Oña, and Rowell, G. P.

Subjects
MOLECULAR clouds, STAR clusters, SUPERNOVAE, QUASARS, X-ray emission spectroscopy
Abstract

We have made new CO observations of two molecular clouds, which we call “jet” and “arc” clouds, toward the stellar cluster Westerlund 2 and the TeV γ-ray source HESS J1023–575. The jet cloud shows a linear structure from the position of Westerlund 2 on the east. In addition, we have found a new counter jet cloud on the west. The arc cloud shows a crescent shape in the west of HESS J1023–575. A sign of star formation is found at the edge of the jet cloud and gives a constraint on the age of the jet cloud to be ∼Myr. An analysis with the multi CO transitions gives temperature as high as 20 K in a few places of the jet cloud, suggesting that some additional heating may be operating locally. The new TeV γ-ray images by H.E.S.S. correspond to the jet and arc clouds spatially better than the giant molecular clouds associated with Westerlund 2. We suggest that the jet and arc clouds are not physically linked with Westerlund 2 but are located at a greater distance around 7.5 kpc. A microquasar with long-term activity may be able to offer a possible engine to form the jet and arc clouds and to produce the TeV γ-rays, although none of the known microquasars have a Myr age or steady TeV γ-rays. Alternatively, an anisotropic supernova explosion which occurred ∼Myr ago may be able to form the jet and arc clouds, whereas the TeV γ-ray emission requires a microquasar formed after the explosion. [ABSTRACT FROM AUTHOR]

Published
2014
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133. Molecular Clouds in the LMC Observed with NANTEN: III. Comparison with HII Regions

Author

Abe, R., primary, Hara, A., additional, Hayakawa, T., additional, Kato, S., additional, Kawamura, A., additional, Mizuno, A., additional, Mizuno, N., additional, Ogawa, H., additional, Onishi, T., additional, Saito, H., additional, Tachihara, K., additional, Xiao, K. C., additional, Yamaguchi, N., additional, Yamaguchi, R., additional, Fukui, Y., additional, and Yonekura, Y., additional

Published
1999
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134. Molecular Clouds in the LMC Observed with NANTEN: II. Comparison with Stellar Clusters

Author

Yamaguchi, R., primary, Abe, R., additional, Hara, A., additional, Hayakawa, T., additional, Kato, S., additional, Kawamura, A., additional, Mizuno, A., additional, Mizuno, N., additional, Ogawa, H., additional, Onishi, T., additional, Saito, H., additional, Tachihara, K., additional, Xiao, K. C., additional, Yamaguchi, N., additional, Fukui, Y., additional, and Yonekura, Y., additional

Published
1999
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135. A 12CO Survey of the LMC with NANTEN

Author

Fukui, Y., primary, Abe, R., additional, Hara, A., additional, Hayakawa, T., additional, Kato, S., additional, Kawamura, A., additional, Mizuno, A., additional, Mizuno, N., additional, Ogawa, H., additional, Onishi, T., additional, Saito, H., additional, Tachihara, K., additional, Xiao, K. C., additional, Yamaguchi, N., additional, Yamaguchi, R., additional, Yonekura, Y., additional, and Rubio, M., additional

Published
1999
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136. Molecular Clouds in the LMC Observed with NANTEN: IV. Comparison with SNRs

Author

Saito, H., primary, Abe, R., additional, Hara, A., additional, Hayakawa, T., additional, Kato, S., additional, Kawamura, A., additional, Mizuno, A., additional, Mizuno, N., additional, Ogawa, H., additional, Onishi, T., additional, Tachihara, K., additional, Xiao, K. C., additional, Yamaguchi, N., additional, Yamaguchi, R., additional, Fukui, Y., additional, and Yonekura, Y., additional

Published
1999
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137. Molecular Clouds in the LMC Observed with NANTEN: I. Physical Properties of the Clouds

Author

Mizuno, N., primary, Abe, R., additional, Hara, A., additional, Hayakawa, T., additional, Kato, S., additional, Kawamura, A., additional, Mizuno, A., additional, Ogawa, H., additional, Onishi, T., additional, Saito, H., additional, Tachihara, K., additional, Xiao, K. C., additional, Yamaguchi, N., additional, Yamaguchi, R., additional, Fukui, Y., additional, and Yonekura, Y., additional

Published
1999
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141. Electrophysiological studies of early stage corticobasal degeneration

Author

Lu, C. S., primary, Ikeda, A., additional, Terada, K., additional, Mima, T., additional, Nagamine, T., additional, Fukuyama, H., additional, Kohara, N., additional, Kojima, Y., additional, Yonekura, Y., additional, Chen, R. S., additional, Tsai, C. H., additional, Chu, N. S., additional, Kimura, J., additional, and Shibasaki, H., additional

Published
1998
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