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J Konishi

Publications and source records attributed to J Konishi.

At least 91 records · Page 5Linked to original sources
PubMed2000

Hyperthyroid Graves' disease after hemithyroidectomy for papillary carcinoma: report of three cases.

Here we report three cases of hyperthyroid Graves' disease that occurred after partial thyroidectomy for papillary carcinoma. In Case 1, the patient first developed hyperthyroidism 2 years after resection of left thyroid lobe, was treated for 2 years with antithyroid drug which was then discontinued, and relapsed with periodic paralysis after 8 years of remission. In Case 2, a hyperfunctioning remnant thyroid was noted 22 years after right hemithyroidectomy. In Case 3, where thyrotoxic symptoms became evident 7 weeks after right hemithyroidectomy, autoantibodies to thyroglobulin and thyroid microsome were positive in preoperative serum, in line with a report by others detecting these antibodies in 2 out of 3 such cases examined. Later bioassay revealed activity of thyroid stimulating antibodies in that serum, with further increase in titer in the sample taken at the clinical manifestation. Hence in Case 3, surgical stress may have altered immunological homeostasis, promoting a preclinical Graves' disease to full-blown hyperthyroidism.

Adult↗
PubMed2000

Percutaneous ethanol injection for treatment of adrenal metastasis from hepatocellular carcinoma.

OBJECTIVE: With the improved prognosis of patients with hepatocellular carcinoma, the likelihood of diagnosing adrenal metastasis has increased. We performed percutaneous ethanol injection for adrenal metastasis in seven patients and evaluated its efficacy. CONCLUSION: Percutaneous ethanol injection was successfully performed in nine nodules in seven patients. During follow-up, six nodules in five patients showed no increase in size. Four patients were alive 6-28 months after injection, one patient died of hepatic failure, one of brain metastasis, and one of multiple metastases. Percutaneous ethanol injection can be an alternative treatment for adrenal metastasis of hepatocellular carcinoma.

Adrenal Gland Neoplasms↗
PubMed2000

Iodinated free fatty acid and 201T1 uptake in chronically hypoperfused myocardium: histologic correlation study.

UNLABELLED: 123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) is a tracer for the evaluation of ischemic heart disease. The purpose of this study was to assess the relationship between 1231-BMIPP uptake and myocardial fibrosis. METHODS: Fifteen patients who underwent cardiac surgery were examined by imaging with 201TI and 123I-BMIPP, and histologic specimens were taken during surgery. The relative uptake of 201TI (%TI) and that of 123I-BMIPP (%BMIPP) were calculated. The percentage of fibrosis (%fibrosis) was analyzed with the specimen. RESULTS: %TI correlated strongly with %fibrosis (r = -0.94; P < 0.001). %BMIPP also correlated significantly with %fibrosis (r = -0.88; P < 0.001), but the change in %BMIPP looked biphasic. In the category of only mild fibrosis, %BMIPP showed a steep decrease. 123I-BMIPP-201TI mismatch was found only for fibrosis <20%. CONCLUSION: 123I-BMIPP gave specific information about metabolic changes that occurred in ischemic myocardium without severe fibrotic changes.

Coronary Disease↗
PubMed2000

[Roles of thymic epithelial cells in generation of NK-T cells from aly/aly mouse].

NK1.1+ TCR alpha/beta+ (NK-T) cells are markedly reduced in the alymphoplasia mutant mouse. We have previously shown that the defect resides in the thymic environment where the NK-T precursors develop but not in the precursor cells themselves. In the present study to elucidate the recipient factor(s) that is responsible for the development of NK-T cells, radiation bone-marrow chimeras were established by using alymphoplasia mutant mice as a donor strain and either beta 2 microglobulin knock-out (beta 2m-/-) or CD1d1-/- mice as recipients, both of which lack CD1 molecules. It was shown that substantial numbers of NK-T cells with typical surface phenotypes were generated both in the thymus and the spleen of the chimeras. The NK-T cells produced equivalent or slightly elevated levels of IL-4 and IFN-gamma in response to an immobilized anti-CD3 monoclonal antibody. These findings suggested that expression of beta 2m-associated ligands, namely CD1 molecules, on the thymic epithelium was not necessarily an essential requisite for the NK-T cell development. Furthermore, we demonstrate herein that the intrathymic transfer of a medullary thymic epithelial cell line of normal mouse can rescue the generation of the NK-T cells in the thymus of alymphoplasia mouse. These results demonstrate that function(s) represented by certain types of thymic epithelial cells is indispensable for development of NK-T cells.

Animals↗
PubMed2000

Noninvasive estimation of FDG input function for quantification of cerebral metabolic rate of glucose: optimization and multicenter evaluation.

UNLABELLED: The aims of this study were to determine whether body weight or body surface area (BSA) should be used for noninvasive measurement of the cerebral metabolic rate of glucose (CMRGlc) by FDG PET with a standardized input function (SIF) and an autoradiographic method and to validate the procedure in a large population from different PET centers. METHODS: Plasma input functions measured by intermittent arterial blood sampling after intravenous injection of FDG, in 101 patients from 1 institution who were fasting for at least 4 h, were used to generate the SIF. The SIF was generated by averaging over 101 patients the input function normalized with the net injected dose and initial distribution volume (DV) of FDG estimated by the formula c x Ha x Wb, where H is body height and W is body weight. To evaluate the estimation of DV by BSA or body weight, the coefficient of variation (CV) of the ratio of Ha x Wb to the measured DV was calculated by changing a and b independently. Estimation of the CMRGlc with SIF based on the formula for DV was validated with an additional 192 subjects from 3 institutions who underwent FDG PET while fasting. The result of simulation was compared with the results of 4 previously published formulas for BSA and body weight. RESULTS: The optimal set of parameters, in which a was 0.80 and b was 0.35, minimized the CV. The averaged percentage error of the CMRGlc based on the optimal set of parameters for DV estimation and SIF was 8.9% for gray matter and 10.6% for white matter. Four BSA formulas brought about a similar error, which was significantly smaller than that based on body weight (P < 0.001, ANOVA). CONCLUSION: Noninvasive estimation of CMRGlc is made possible by careful measurement of the net injected dose and BSA.

Autoradiography↗
PubMed2000

Establishment and characterization of a breast cancer cell line expressing Na+/I- symporters for radioiodide concentrator gene therapy.

UNLABELLED: 131I therapy is a widely accepted treatment for metastatic differentiated thyroid cancer. To investigate the feasibility of 131I therapy for breast cancer, we established breast cancer cells stably expressing Na-/I- symporter (NIS) gene that can be modulated and studied in vitro and in vivo. METHODS: We transfected rat NIS genes into a human breast cancer cell line (MCF7) by electroporation. Iodide accumulation was evaluated under various extracellular concentrations of sodium and iodide, and iodide efflux was also assessed. Biodistribution and tumor imaging were studied using tumor-bearing mice. RESULTS: A novel cell line (MCF3B), stably expressing the NIS gene, was established from MCF7. MCF3B took up 44 times more radioiodide in vitro than MCF7 did. Iodide uptake was completely inhibited by 1 mmol/L perchlorate and was dependent on external sodium and iodide concentrations. Iodide efflux from MCF3B cells was slower (half-life [T 1/2] > 27 min) than from FRTL5 thyroid cells (T 1/2 = 4 min). In the biodistribution study using MCF3B-xenografted mice, high tumor uptake of 125I was shown (16.73%) at 1 h after injection, and tumor-to-normal tissue ratios were also high (4.84-21.28), except in the stomach (0.47). However, the iodide accumulation in the tumor lessened with time, reaching less than 1% at 24 h after injection. CONCLUSION: Our preliminary data indicate that NIS-based gene therapy may be applied by concentrating a lethal dose of radiation in tumor cells in vivo, but further investigation is necessary to determine a method of maintaining radioiodine in the cells to allow greater therapeutic effects.

Animals↗
PubMed2000

[Recent progress in radionuclide therapy].

Therapeutic use of radionuclides includes 131I for thyroid cancer and hyperthyroid Graves' disease, 89SrCl3 for metastatic bone tumors, 131I-MIBG for malignant pheochromocytoma and neuroblastoma, and radioimmunotherapies. 131I is concentrated in 60-70% of metastases from differentiated thyroid cancer following total thyroidectomy. Radioiodine uptake in metastatic lesions is greater in younger patients than in older ones. Hypothyroidism is often mild or even absent in patients with a large amount of tumor tissue, indicating that thyroid hormones produced by highly differentiated tumors compensate partially or even completely for hypothyroidism following total thyroidectomy. Adequate uptake of 131I has been reported to be associated with significant reduction in the size and number of metastases, and with lower recurrence and higher survival rates. Other favorable factors for longer survival are younger age, well-differentiated histological type, small disease extent, and early discovery of metastases. Older patients with extensive metastases and/or bulky tumor masses in the bone have a poor prognosis. Therefore, it is important to discover metastases as early as possible, when patients are still young. Long-term follow-up with periodic thyroglobulin measurements and imaging studies is strongly recommended. In Japan, 131I treatment for Graves' disease is performed only in selected patients in whom antithyroid drugs cannot be used because of side effects or not effective, considering the high prevalence of permanent hypothyroidism. 89SrCl3 is useful for reducing pain due to bone metastases of malignant tumors. 131I-MIBG therapy is effective for improvement of QOL in some patients with metastatic malignant pheochromocytoma. Radioimmuno-therapy using anti-CD20 has been used successfully in clinical application in patients with malignant B cell lymphoma.

3-Iodobenzylguanidine↗
PubMed2000

Microtensile bond strength to dentin and cavity adaptation of Cerec 2 inlay restoration.

PURPOSE: To examine the bond strength of Cerec 2 inlays both to dentin surface by microtensile testing and to cavity walls by cavity adaptation in Class II restorations, using three luting materials. MATERIAL AND METHODS: VitaMark II disc was bonded to the coronal dentin surface with Clapearl DC (Clearfil DC)/Linerbond IIsigma (Linerbond 2V), AP-X/Linerbond IIsigma or Fluorocement (Panavia F)/ED Primer. After 24-hr storage in water, microtensile bond strengths (MTB) were measured. Additionally, Cerec inlays were luted to the MO cavities prepared in molars with the same materials. After thermocycling (x2000), the restorations were sectioned mesio-distally. Gap formation was microscopically examined along the cavity walls. RESULTS: There was no significant difference in MTB among the materials (Clapearl DC: 20.89 +/- 4.58 MPa, AP-X: 24.22 +/- 5.97 MPa, Fluorocement: 19.82 +/- 6.43 MPa, Scheffé, P > 0.05). The frequency of gap formation was higher in AP-X than in Clapearl DC and Fluorocement (chi2-test, P < 0.05). Debonding occurred more often at the luting material/dentin interface than at the inlay/luting material interface (Sign test, P < 0.05).

Analysis of Variance↗
PubMed1999

Brain arteriolosclerosis and hemodynamic disturbance may induce leukoaraiosis.

OBJECTIVE: To investigate whether internal carotid artery (ICA) occlusive disease-induced hemodynamic disturbance is associated with extensive white matter high-intensity lesions (WMLs) on T2-weighted MR images in the hemisphere with lacunar infarct in the basal ganglia. BACKGROUND: Hemodynamic disturbance in the brain with arteriolosclerosis may be one of the mechanisms by which ischemic injury induces extensive WMLs. METHODS: The authors used MRI and PET to study 21 patients with unilateral ICA occlusion or stenosis and lacunar infarct in the bilateral basal ganglia. In hemispheres with ICA disease, the association of WMLs with the mean hemispheric values of oxygen extraction fraction (OEF)-an index of hemodynamic compromise-measured with the 15O-labeled gas steady-state technique was analyzed. Twenty-five patients with ICA occlusive disease without lacunar infarct were studied as control subjects. RESULTS: In the hemispheres with ICA disease, patients with lacunar infarct had a significantly greater severity of WMLs than control subjects, although the mean hemispheric values of the OEF showed no significant difference. The severity of WMLs correlated significantly with the mean hemispheric values of the OEF in patients with lacunar infarct, but not in control subjects. Multivariate analysis revealed that lacunar infarcts and increased OEF were independent predictors of extensive WMLs, with lacunar infarcts the most heavily weighted factor. CONCLUSION: Internal carotid artery occlusive disease-induced hemodynamic disturbance is associated with extensive WMLs in hemispheres with lacunar infarct. Hemodynamic disturbance may contribute to the development of extensive WMLs, although brain arteriolosclerosis may be a major contributing factor.

Aged↗
PubMed1999

Activities of the primary and supplementary motor areas increase in preparation and execution of voluntary muscle relaxation: an event-related fMRI study.

Brain activity associated with voluntary muscle relaxation was examined by applying event-related functional magnetic resonance imaging (fMRI) technique, which enables us to observe change of fMRI signals associated with a single motor trial. The subject voluntarily relaxed or contracted the right upper limb muscles. Each motor mode had two conditions; one required joint movement, and the other did not. Five axial images covering the primary motor area (M1) and supplementary motor area (SMA) were obtained once every second, using an echoplanar 1.5 tesla MRI scanner. One session consisted of 60 dynamic scans (i.e., 60 sec). The subject performed a single motor trial (i.e., relaxation or contraction) during one session in his own time. Ten sessions were done for each task. During fMRI scanning, electromyogram (EMG) was monitored from the right forearm muscles to identify the motor onset. We calculated the correlation between the obtained fMRI signal and the expected hemodynamic response. The muscle relaxation showed transient signal increase time-locked to the EMG offset in the M1 contralateral to the movement and bilateral SMAs, where activation was observed also in the muscle contraction. Activated volume in both the rostral and caudal parts of SMA was significantly larger for the muscle relaxation than for the muscle contraction (p < 0.05). The results suggest that voluntary muscle relaxation occurs as a consequence of excitation of corticospinal projection neurons or intracortical inhibitory interneurons, or both, in the M1 and SMA, and both pre-SMA and SMA proper play an important role in motor inhibition.

Adult↗
PubMed1999

Indian hedgehog in the late-phase differentiation in mouse chondrogenic EC cells, ATDC5: upregulation of type X collagen and osteoprotegerin ligand mRNAs.

Endochondral bone formation includes a cascade of cellular events such as proliferation, maturation, hypertrophic conversion and calcification of chondrocytes and the cartilage replacement by bone. During these processes, hypertrophic conversion and calcification of chondrocytes (the late-phase differentiation) is a crucial process of chondrogenic differentiation. Indian hedgehog (Ihh), a secreted protein expressed in early hypertrophic chondrocytes, is thought to be involved in regulation of hypertrophic conversion via a feedback loop through the perichondrium. In the present study, we showed by Northern analysis and in situ hybridization that Smoothened (Smo), a key component in hedgehog signal transduction, was expressed in chondrocytes in both adult mice and mouse embryos at 16 days post-coitum in vivo, suggesting that Ihh directly acts on chondrocytes. We previously reported that Ihh, Patched and Smo were all expressed in differentiated ATDC5 cells. Exogenously administered mouse recombinant N-terminal protein of Ihh (mrIhh-N) upregulated the gene expression of type X collagen, a phenotypic marker of hypertrophic chondrocytes, as well as osteoprotegerin ligand (OPGL), a potent stimulator of osteoclastogenesis and osteoclast activity, while it did not modulate the expression of Ihh itself, bone morphogenetic protein (BMP)-4, BMP-6, transforming growth factor (TGF)-beta1 and TGF-beta2 in differentiated ATDC5 cells. Moreover, when added to the osteoclast cultures, mrIhh-N markedly stimulated the formation of resorption pits on dentine slices. Our data support the hypothesis that Ihh stimulated the late-phase chondrogenic differentiation in differentiated ATDC5 cells and upregulated the gene expression of OPGL in these cells.

Alveolar Bone Loss↗
PubMed1999

Assessment of regional and global left ventricular function by reinjection T1-201 and rest Tc-99m sestamibi ECG-gated SPECT: comparison with three-dimensional magnetic resonance imaging.

OBJECTIVES: The purpose of this study was to test the ability of reinjection thallium-201 and rest technetium-99m sestamibi ECG (electrocardiographic)-gated SPECT (i.e., reinjection-g-SPECT [single-photon emission computed tomography] and MIBI-g-SPECT) to determine regional and global functional parameters. BACKGROUND: The ECG-gated perfusion SPECT was reported to provide accurate left ventricular ejection fraction (LVEF) using an automated algorithm. We hypothesized that other various functional data may be obtained using reinjection-g-SPECT and MIBI-g-SPECT. METHODS: Reinjection-g-SPECT, MIBI-g-SPECT, and three-dimensional magnetic resonance imaging (3DMRI) were conducted in 20 patients with coronary artery disease. Regional wall motion (RWM) and wall thickening (RWT) were analyzed using semiquantitative visual scoring by each g-SPECT and 3DMRI. The left ventricular end-systolic and end-diastolic volumes (EDV, ESV) and LVEF estimated by reinjection- and MIBI-g-SPECT were compared with the results of 3DMRI. RESULTS: A high degree of agreement in RWM and RWT assessment was observed between each g-SPECT and 3DMRI (kappa >.70, p < .001). The LVEF values by reinjection- and MIBI-g-SPECT correlated and agreed well with those by 3DMRI (reinjection: r = .92, SEE = 5.9%, SD of differences = 5.7%; sestamibi: r = .94, SEE = 4.4%, SD of differences = 5.1%). The same also pertained to EDV (reinjection: r = .85, SEE = 18.7 ml, SD of differences = 18.4 ml; sestamibi: r = .92, SEE = 13.1 ml, SD of differences = 13.0 ml) and ESV (reinjection: r = .94, SEE = 10.3 ml, SD of differences = 10.3 ml; sestamibi: r = .97, SEE = 6.7 ml [p < .05 vs. reinjection by F test], SD of differences = 6.6 ml [p < .05 vs. reinjection by F test]). CONCLUSIONS: Reinjection- and MIBI-g-SPECT provide clinically satisfactory various functional data. These functional data in combination with the perfusion information will improve diagnostic and prognostic accuracy without an increase in cost or the radiation dose to the patients.

Adult↗
PubMed1999

Cloning of a novel gene specifically expressed in clonal mouse chondroprogenitor-like EC cells, ATDC5.

We cloned a full-length cDNA encoding a novel mouse protein, A-C2, by differential display method using mouse embryonic fibroblast C3H10T1/2 cells and mouse chondroprogenitor-like EC cells, ATDC5. The deduced amino acid sequence of A-C2 consisted of 106 amino acids with no significant homology to the sequences previously reported. Northern blot analysis showed two major bands of 2.1 and 1.8 kb sizes. Expression of A-C2 mRNA was exclusive to ATDC5 cells at their undifferentiated stage. None of ATDC5 cells at their differentiated stage and adult mice tissues examined expressed A-C2 gene.

Amino Acid Sequence↗
PubMed1999

Chemical design of radiolabeled antibody fragments for low renal radioactivity levels.

The renal uptake of radiolabeled antibody fragments presents a problem in targeted imaging and therapy. We hypothesized that the renal radioactivity levels of radiolabeled antibody fragments could be reduced if radiolabeled compounds of urinary excretion were released from glomerularly filtered antibody fragments before they were incorporated into renal cells by the action of brush border enzymes, present on the lumen of renal tubules. 3'-[131I]Iodohippuryl N(epsilon)-maleoyl-L-lysine ([131I]HML) was conjugated with a thiolated Fab fragment because the glycyl-lysine sequence in HML is a substrate for a brush border enzyme and metaiodohippuric acid is released by cleavage of the linkage. Fab fragments were also radiolabeled by direct radioiodination (125I-Fab) or by conjugation with meta-[125I]-iodohippuric acid via an amide bond [N-(5-maleimidopentyl) 3'-iodohippuric acid amide ([125I]MPH-Fab)] or an ester bond [maleimidoethy 3'-iodohippurate ([125I]MIH-Fab)] by procedures similar to those used for [131I]HML-Fab. In biodistribution experiments in mice, [131I]HML-Fab demonstrated markedly low renal radioactivity levels with kidney:blood ratios of radioactivity of 1 from 10 min to 1 h due to rapid release of meta-[131I]iodohippuric acid. [125]MIH-Fab and 1251-Fab reached their peak ratios of 3.8 and 7.3 at 1 h, respectively, and [125I]MPH-Fab showed the maximum ratio of 16.8 at 6 h. In subcellular distribution studies, both [125I]MIH-Fab and 125I-Fab showed migration of radioactivity from the membrane to the lysosomal fraction of the renal cells from 10 to 30 min postinjection, whereas the majority of the radioactivity was detected only in the membrane fraction after administration of [131I]HML-Fab at both time points. In nude mice, [131I]HML-Fab showed one-quarter of the renal radioactivity of simultaneously administered 125I-Fab without impairing the target radioactivity levels 3 h after injection. These findings indicated that HML is a useful reagent for targeted imaging and therapy using antibody fragments as vehicles. These findings also suggested that the radiochemical design of radiolabeled antibody fragments that liberate radiometabolites of urinary excretion from antibody fragments by the action of brush border enzymes may constitute a new strategy for reducing the renal radioactivity levels of antibody fragments.

Animals↗
PubMed1999

In vitro analysis of the stimulation of bone formation by highly bioactive apatite- and wollastonite-containing glass-ceramic: released calcium ions promote osteogenic differentiation in osteoblastic ROS17/2.8 cells.

We analyzed the mechanisms of the efficient bone formation on the osteoconductive surface of apatite- and wollastonite-containing glass-ceramic (AW) by using an in vitro system. AW releases Ca ions and bonds to bone via a submicron-thick hydroxycarbonate apatite (HCA) layer. AW disks were conditioned with simulated body fluid (SBF) to grow HCA layers, and the amount of released Ca ion was regulated by modulating the conditioning time from 24 to 240 h. Surface-transformed AW disks increased alkaline phosphatase (AP) activity in osteoblastic ROS17/2.8 cells by 1.5- to threefold over unconditioned disks. AW disks conditioned for 24 h [AW(24)], which had a homogeneous, submicron-thick apatite layer and increased extracellular ionized Ca concentration ([Ca(2+)](e)) in the culture medium to the greatest extent, enhanced the AP activity the most. High [Ca(2+)](e) promoted osteogenic differentiation in ROS17/2.8 cells: It increased AP activity in a dose-dependent manner by up to 1.6-fold, and up-regulated the expression of AP, osteocalcin (OC), and transforming growth factor-beta1 mRNAs in dose- and time-dependent manners. AW(24) enhanced AP activity in ROS17/2.8 cells as much as AW disks conditioned with SBF containing serum to exhibit in vivo surface-structure changes. AW(24) increased AP activity in ROS17/2.8 cells by 1.6-fold and enhanced the expression of AP and OC mRNAs significantly, compared with sintered hydroxyapatite (HA). After implantation of AW and HA in the distal metaphyses of rabbit femurs, thin, newly formed bone lined with cuboidal, osteoblast-like cells was characteristically observed adjacent to the AW surface within 8 days. These results provide evidence for the hypothesis that AW stimulates bone formation on its surface by increasing [Ca(2+)](e) to promote the HCA layer formation and the differentiation of osteogenic cells.

Animals↗
PubMed1999

Thymic microenvironment and NZB mice: the abnormal thymic microenvironment of New Zealand mice correlates with immunopathology.

There are distinct microenvironmental abnormalities of thymic architecture in several murine models of SLE defined using immunohistochemistry and a panel of mAb dissected at thymic epithelial markers. To address the issue of the relationship between the thymic microenvironment and autoimmunity, we studied backcross (NZB x NZW) F1 x NZW mice in which 50% of offspring develop nephritis associated with proteinuria and anti-DNA antibodies. We reasoned that if thymic abnormalities are associated with development of disease, the correlation of abnormalities with lupus-like disease in individual backcross mice will form the foundation for identification of the mechanisms involved. In parallel, we directed a genetic linkage analysis, using markers previously shown to be linked to nephritis and IgG autoantibody production, to determine if such loci were similarly associated with microenvironmental changes. Our data demonstrate that all (NZB x NZW) F1 x NZW backcross mice with disease have microenvironmental defects. Although the microenvironmental defects are not sufficient for development of autoimmune disease, the severity of thymic abnormalities correlates with titers of IgG autoantibodies to DNA and with proteinuria. Consistent with past studies of (NZB x NZW) F1 x NZW mice, genetic markers on proximal chromosome 17 (near MHC) and distal chromosome 4 showed trends for linkage with nephritis. Although the markers chosen only covered about 10-15% of the genome, the results demonstrated trends for linkage with thymic medullary abnormalities for loci on distal chromosome 4 and distal chromosome 1. We believe it will be important to define the biochemical nature of the molecules recognized by these mAbs to understand the relationships between thymic architecture and immunopathology.

Animals↗
PubMed1999

Transient neural activity in the medial superior frontal gyrus and precuneus time locked with attention shift between object features.

To investigate the contribution of the superior frontal gyrus and precuneus to the cognitive process of attention set shift, we examined the correlation between change in neural activity in these areas and the timing of attention set shift using event-related functional magnetic resonance imaging. Seven subjects underwent a card-sorting task in which they matched a test card to one of two target cards according to color or shape. The subjects had to determine the correct category based only on feedback and shift the sorting principle when the feedback changed from "correct" to "incorrect." Transient increase of neural activity time locked with attention shift phases was detected in the medial superior frontal gyrus (the rostral part of the supplementary motor area) and precuneus. During the control task, in which the feedback and the motor responses were preserved without any attention shift, this type of change in neural activity was not observed. Our findings indicate that increase in neural activity in these brain areas may be closely related to attention set shift between object features and suggest that these areas may play a role in the shifting of cognitive sets.

Adult↗