Hidehiko Okazawa

Prof. Dr. Hidehiko Okazawa

University of Fukui
orcid

Research Focus & Metrics

Academic Career Length

37Years (1990-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2001 in American Journal of Psychiatry
Verified
Journal Article
Closed access
MLMarco Leyton
Marco Leyton
Hidehiko OkazawaHidehiko Okazawa
Hidehiko Okazawa
MDMirko Diksic
Mirko Diksic
JPJoel Paris
Joel Paris
PRPedro Rosa-Neto
Pedro Rosa-Neto
CBChawki Benkelfat
Chawki Benkelfat

1 January 2010 in Frontiers in Integrative Neuroscience
Verified
Journal Article
Open access
DSDaisuke N. Saito
Daisuke N. Saito
HTHiroki C. Tanabe
Hiroki C. Tanabe
KIKeise Izuma
Keise Izuma
MHMasamichi J. Hayashi
Masamichi J. Hayashi
YMYusuke Morito
Yusuke Morito
NSNorihiro Sadato
Norihiro Sadato
Eye contact provides a communicative link between humans, prompting joint attention. As spontaneous brain activity may have an important role in coordination of neuronal processing within the brain, their inter-subject synchronization may occur during eye contact. To test this, we conducted simultaneous functional MRI in pairs of adults. Eye contact was maintained at baseline while the subjects engaged in real-time gaze exchange in a joint attention task. Averted gaze activated the bilateral occipital pole extending to the right posterior superior temporal sulcus, the dorso-medial prefrontal cortex, and bilateral inferior frontal gyrus. Following a partner’s gaze towards an object activated the left intraparietal sulcus. After all task-related effects were modeled out, inter-individual correlation analysis of residual time-courses was performed. Paired subjects showed more prominent correlations than non-paired subjects in the right inferior frontal gyrus, suggesting that this region is involved in sharing intention during eye contact that provides the context for joint attention.

17 January 2004 in European Journal of Nuclear Medicine and Molecular Imaging
Verified
Journal Article
Closed access
PDF file
AIAkihiko Iida
Akihiko Iida
Hidehiko OkazawaHidehiko Okazawa
Hidehiko Okazawa
KHKohei Hayashida
Kohei Hayashida
NTNaohiro Tsuyuguchi
Naohiro Tsuyuguchi
KIKazunari Ishii
Kazunari Ishii
YOYasuomi Ouchi
Yasuomi Ouchi

11 June 2014 in Molecular Autism
Verified
Journal Article
Open access
PDF file
MJMinyoung Jung
Minyoung Jung
HKHirotaka Kosaka
Hirotaka Kosaka
DSDaisuke N Saito
Daisuke N Saito
MIMakoto Ishitobi
Makoto Ishitobi
TMTomoyo Morita
Tomoyo Morita
TITetsuya Iidaka
Tetsuya Iidaka
Autism spectrum traits are postulated to lie on a continuum that extends between individuals with autism and individuals with typical development (TD). Social cognition properties that are deeply associated with autism spectrum traits have been linked to functional connectivity between regions within the brain’s default mode network (DMN). Previous studies have shown that the resting-state functional connectivities (rs-FCs) of DMN are low and show negative correlation with the level of autism spectrum traits in individuals with autism spectrum disorder (ASD). However, it is unclear whether individual differences of autism spectrum traits are associated with the strength of rs-FCs of DMN in participants including the general population. Using the seed-based approach, we investigated the rs-FCs of DMN, particularly including the following two core regions of DMN: the anterior medial prefrontal cortex (aMPFC) and posterior cingulate cortex (PCC) in 19 young male adults with high-functioning ASD (mean age = 25.3 ± 6.9 years; autism-spectrum quotient (AQ) = 33.4 ± 4.2; full scale IQ (F-IQ) = 109.7 ± 12.4) compared with 21 age- and IQ-matched young male adults from the TD group (mean age = 24.8 ± 4.3 years; AQ = 18.6 ± 5.7; F-IQ = 109.5 ± 8.7). We also analyzed the correlation between the strength of rs-FCs and autism spectrum traits measured using AQ score. The strengths of rs-FCs from core regions of DMN were significantly lower in ASD participants than TD participants. Under multiple regression analysis, the strengths of rs-FCs in brain areas from aMPFC seed showed negative correlation with AQ scores in ASD participants and TD participants. Our findings suggest that the strength of rs-FCs in DMN is associated with autism spectrum traits in the TD population as well as patients with ASD, supporting the continuum view. The rs-FCs of DMN may be useful biomarkers for the objective identification of autism spectrum traits, regardless of ASD diagnosis.

3 February 2004 in International Journal of Cancer
Verified
Journal Article
Open access
PDF file
TKTetsuji Kurokawa
Tetsuji Kurokawa
YYYoshio Yoshida
Yoshio Yoshida
KKKazumi Kawahara
Kazumi Kawahara
TTTatsuro Tsuchida
Tatsuro Tsuchida
Hidehiko OkazawaHidehiko Okazawa
Hidehiko Okazawa
FKFumikazu Kotsuji
Fumikazu Kotsuji
We evaluated whether tracer FDG uptake, quantified as an SUV by PET in ovarian epithelial tumors, correlates with clinical stage, tumor grade, cell proliferation and glucose metabolism, all of which are biomarkers for response to chemotherapy, prognosis and overall survival in ovarian cancer patients. Seventeen patients suspected of having ovarian cancer by physical examination, tumor marker analysis and anatomic imaging (such as sonography, CT and/or MRI) underwent whole‐body FDG‐PET within the 2 weeks prior to surgery. Seventeen epithelial ovarian tumor specimens (13 malignant tumors, 5 at stage I, 2 at stage II, 6 at stage III; 2 borderline tumors; and 2 benign lesions) were available for pathologic evaluation. They were graded histopathologically, and immunohistochemistry for MIB‐1 (proliferation index marker) and GLUT‐1 was performed. Correlation between FDG uptake and clinical stage, GLUT‐1 expression, MIB‐1 LI and histologic grading score was determined. No positive correlation was observed between FDG uptake and clinical stage (p = 0.14). Intensity of GLUT‐1 expression (r = 0.76, p = 0.001), MIB‐1 LI (r = 0.457, p = 0.014) and histologic grading score (r = 0.692, p = 0.005) showed statistically significant positive correlations with FDG uptake. Stepwise logistic regression analysis revealed that expression of GLUT‐1 transporters was the strongest parameter (r = 0.760, p = 0.0004) by which to predict positive FDG uptake. Therefore, glucose consumption, as determined by analysis of SUVs in FDG‐PET, may be a noninvasive biomarker for ovarian epithelial tumors.

1 January 2004 in American Journal of Roentgenology
Verified
Journal Article
Closed access
YYYoshio Yoshida
Yoshio Yoshida
TKTetsuji Kurokawa
Tetsuji Kurokawa
KKKazumi Kawahara
Kazumi Kawahara
TTTatsuro Tsuchida
Tatsuro Tsuchida
Hidehiko OkazawaHidehiko Okazawa
Hidehiko Okazawa
FKFumikazu Kotsuji
Fumikazu Kotsuji
OBJECTIVE. The purpose of this study was to determine whether the addition of positron emission tomography (PET) with the radiotracer FDG to cross-sectional imaging, such as CT, increases accuracy in the detection of tumor spread.SUBJECTS AND METHODS. Fifteen patients who were thought to have ovarian cancer on the basis of the results of physical examination, sonography findings, and level of serum cancer antigen 125 were enrolled over an 11-month period. After screening, patients underwent two imaging examinations—abdominopelvic CT and whole-body FDG PET— within 2 weeks before surgery. Also before surgery, staging accuracy was assessed separately using CT with or without FDG PET (which was based on modifications of the International Federation of Gynecology and Obstetrics [FIGO] criteria). The results of the histology and surgery findings were used to assess the accuracy of the scanning findings.RESULTS. Staging revealed stage III disease in seven patients (IIIC, n = 6; IIIB, n = 1), stage II in three (I...