Toshiki Shioiri

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Nicotianamine aminotransferase (NAAT), the key enzyme involved in the biosynthesis of mugineic acid family phytosiderophores (MAs), catalyzes the amino transfer of nicotianamine (NA). MAs are found only in graminaceous plants, although NA has been detected in every plant so far investigated. Therefore, this amino transfer reaction is the first step in the(More)
The incidence of cavum septum pellucidum (CSP), which has been widely regarded as a developmental anomaly of little clinical importance in neuropathology, was examined in 113 patients with affective disorders (69 with bipolar disorder and 44 with major depression), 40 schizophrenic patients, and 92 control subjects by magnetic resonance imaging (MRI).(More)
Frontal lobe dysfunction has been linked to negative symptoms of schizophrenia. We used phosphorus-31 magnetic resonance spectroscopy (31P-MRS) to examine phosphorous metabolism in frontal brain regions in 26 schizophrenic patients compared with 26 sex- and age-matched control subjects. The relative signal intensities of phosphorous metabolites in frontal(More)
The authors have previously reported decreased intracellular pH (pHi) in the frontal lobes in euthymic bipolar patients treated with lithium using 31P-MRS. White matter hyperintensity (WMHI) is frequently seen in bipolar disorder. To examine a possible effect of lithium on pHi and the relationship between pHi and WMHI, seven drug-free euthymic bipolar(More)
Phosphorus-31 magnetic resonance spectroscopy (MRS), able to detect membrane metabolism and intracellular pH as well as energy metabolism in vivo, was applied to 17 bipolar patients in the manic state and the euthymic state. In nine of these patients, brain lithium concentration was simultaneously determined by means of lithium-7 MRS in order to clarify the(More)
Brain phosphorus metabolism was measured in 22 patients with depressive disorders. Ten of them had DSM-III-R bipolar disorder, and 12 had major depression. In bipolar patients, phosphomonoester (PME) and intracellular pH were significantly increased in the depressive state than in the euthymic state, while those values in the euthymic state were(More)
Brain lithium concentrations were measured in eight patients with affective disorders using lithium-7 magnetic resonance spectroscopy (MRS). Brain lithium concentrations correlated better with serum concentrations (n = 23, r = 0.66, p < 0.001) than with erythrocyte concentrations (r = 0.44, p < 0.05). Because of previous data in animal experiments these(More)
Brain phosphorus metabolism was measured by 31P-MRS in 15 patients with bipolar II disorder (BP II) and 14 patients with bipolar I disorder (BP I). Phosphocreatine (PCr)levels were significantly lower in patients with BP II in all three psychiatric states compared to 59 normal controls (PCr (%) was 13.5 +/- 1.5 (mean +/- SD) for controls, and 12.2 +/- 1.7,(More)
Effect of photic stimulation (PS) on energy metabolism in the human occipital cortex was examined by using phosphorus-31 magnetic resonance spectroscopy in 9 normal subjects. Phosphocreatine (PCr)/total phosphorus signal peak area ratio significantly decreased from 12.3% to 10.9% during the 12 minutes of PS (P < 0.05). PCr once returned to a normal level(More)