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Dive into the research topics where George Imataka is active.

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Featured researches published by George Imataka.


Brain & Development | 2009

Outcome of acute necrotizing encephalopathy in relation to treatment with corticosteroids and gammaglobulin

Akihisa Okumura; Masashi Mizuguchi; Hiroyuki Kidokoro; Manabu Tanaka; Sinpei Abe; Mitsuaki Hosoya; Hideo Aiba; Yoshihiro Maegaki; Hitoshi Yamamoto; Takuya Tanabe; Eiko Noda; George Imataka; Hirokazu Kurahashi

OBJECTIVE To examine the relation between outcome and treatment with steroids and gammaglobulin in children with acute necrotizing encephalopathy. METHODS We retrospectively evaluated the clinical course and outcome of 34 children with acute necrotizing encephalopathy. They were divided into two groups; 17 patients with brainstem lesion and 17 patients without brainstem lesion. Early steroid use was defined as when steroids were administered within 24h after the onset. The outcome was judged as good when a patient had no or mild cognitive impairment and poor when a patient had more severe sequelae, or died. RESULTS Among patients without brainstem lesions, the outcome was good in 7 of 12 with early steroid, whereas it was poor in all 5 patients without early steroid. There was no significant difference in sex, age, and laboratory data between patients with and without early steroid. The outcome was not correlated with gammaglobulin treatment. As to patients without brainstem lesions, the outcome was not correlated with early steroid or gammaglobulin treatment. CONCLUSIONS Steroid within 24 h after the onset was related to better outcome of children with acute necrotizing encephalopathy without brainstem lesions. Early steroid treatment will be an important option of the treatment for acute necrotizing encephalopathy.


Congenital Anomalies | 2007

Dandy-Walker syndrome and chromosomal abnormalities

George Imataka; Hideo Yamanouchi; Osamu Arisaka

ABSTRACT  Dandy–Walker syndrome (DWS) is a brain malformation of unknown etiology, but several reports have been published indicating that there is a causal relationship to various types of chromosomal abnormalities and malformation syndromes. In the present article, we present a bibliographical survey of several previously issued reports on chromosomal abnormalities associated with DWS, including our case of DWS found in trisomy 18. There are various types of chromosomal abnormalities associated with DWS; most of them are reported in chromosome 3, 9, 13 and 18. We also summarize some other chromosomal abnormalities and various congenital malformation syndromes.


Neuromuscular Disorders | 2011

Inflammatory changes in infantile-onset LMNA-associated myopathy.

Hirofumi Komaki; Yukiko K. Hayashi; Rie Tsuburaya; Kazuma Sugie; Mitsuhiro Kato; Toshiro Nagai; George Imataka; Shuhei Suzuki; Shinji Saitoh; Naoko Asahina; Kazuya Honke; Yoshihisa Higuchi; Hiroshi Sakuma; Yoshiaki Saito; Eiji Nakagawa; Kenji Sugai; Masayuki Sasaki; Ikuya Nonaka; Ichizo Nishino

Mutations in LMNA cause wide variety of disorders including Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy, and congenital muscular dystrophy. We recently found a LMNA mutation in a patient who was previously diagnosed as infantile onset inflammatory myopathy. In this study, we screened for LMNA mutations in 20 patients suspected to have inflammatory myopathy with onset at 2years or younger. The diagnosis of inflammatory myopathy was based on muscle pathology with presence of perivascular cuffing and/or endomysial/perimysial lymphocyte infiltration. We identified heterozygous LMNA mutations in 11 patients (55%), who eventually developed joint contractures and/or cardiac involvement after the infantile period. Our findings suggest that LMNA mutation should be considered in myopathy patients with inflammatory changes during infancy, and that this may help avoid life-threatening events associated with laminopathy.


Epilepsia | 2012

Acute encephalopathy in children with Dravet syndrome

Akihisa Okumura; Mitsugu Uematsu; George Imataka; Manabu Tanaka; Tohru Okanishi; Tetsuo Kubota; Akira Sudo; Jun Tohyama; Megumi Tsuji; Iori Ohmori; Misako Naiki; Ayako Hiraiwa-Sofue; Hitoshi Sato; Shinji Saitoh; Toshiaki Shimizu

Purpose:  The occurrence of acute encephalopathy in children with Dravet syndrome has been reported sporadically. This study clarified the features of acute encephalopathy in children with Dravet syndrome.


American Journal of Medical Genetics Part A | 2014

The Spectrum of ZEB2 Mutations Causing the Mowat-Wilson Syndrome in Japanese Populations

Yasukazu Yamada; Noriko Nomura; Kenichiro Yamada; Mari Matsuo; Yuka Suzuki; Kiyoko Sameshima; Reiko Kimura; Yuto Yamamoto; Daisuke Fukushi; Yayoi Fukuhara; Naoko Ishihara; Eriko Nishi; George Imataka; Hiroshi Suzumura; Shin Ichiro Hamano; Kenji Shimizu; Mie Iwakoshi; Kazunori Ohama; Akira Ohta; Hiroyuki Wakamoto; Mitsuharu Kajita; Kiyokuni Miura; Kenji Yokochi; Kenjiro Kosaki; Tatsuo Kuroda; Rika Kosaki; Yoko Hiraki; Kayoko Saito; Seiji Mizuno; Kenji Kurosawa

Mowat–Wilson syndrome (MWS) is a multiple congenital anomaly syndrome characterized by moderate or severe intellectual disability, a characteristic facial appearance, microcephaly, epilepsy, agenesis or hypoplasia of the corpus callosum, congenital heart defects, Hirschsprung disease, and urogenital/renal anomalies. It is caused by de novo heterozygous loss of function mutations including nonsense mutations, frameshift mutations, and deletions in ZEB2 at 2q22. ZEB2 encodes the zinc finger E‐box binding homeobox 2 protein consisting of 1,214 amino acids. Herein, we report 13 nonsense and 27 frameshift mutations from 40 newly identified MWS patients in Japan. Although the clinical findings of all the Japanese MWS patients with nonsense and frameshift mutations were quite similar to the previous review reports of MWS caused by nonsense mutations, frameshift mutations and deletions of ZEB2, the frequencies of microcephaly, Hirschsprung disease, and urogenital/renal anomalies were small. Patients harbored mutations spanning the region between the amino acids 55 and 1,204 in wild‐type ZEB2. There was no obvious genotype–phenotype correlation among the patients. A transfection study demonstrated that the cellular level of the longest form of the mutant ZEB2 protein harboring the p.D1204Rfs*29 mutation was remarkably low. The results showed that the 3′‐end frameshift mutation of ZEB2 causes MWS due to ZEB2 instability.


Cell Biochemistry and Biophysics | 2012

Chromosome Analysis Using Spectral Karyotyping (SKY)

George Imataka; Osamu Arisaka

Spectral karyotyping is a novel technique for chromosome analysis that has been developed based on the approach of the fluorescence in situ hybridization technique. Spectral karyotyping makes it feasible to diagnose a variety of diseases, because of its technology in painting each of the 24 human chromosomes with different colors. In recent years, it has become possible to adopt the usage of spectral karyotyping for research in general clinical practice, and its usability has attracted particular attention in the diagnosis of different diseases. In this review, we will explain the principle of the spectral karyotyping, as well as its specificity and limitation in detecting the genetic defects within clinical application by presenting two case reports.


Current Neuropharmacology | 2015

Eicosanoids Derived From Arachidonic Acid and Their Family Prostaglandins and Cyclooxygenase in Psychiatric Disorders

Kunio Yui; George Imataka; Hiroyuki Nakamura; Naoki Ohara; Yukiko Naito

Arachidonic acid (AA)-derived lipid mediators are called eicosanoids. Eicosanoids have emerged as key regulators of a wide variety of physiological responses and pathological processes, and control important cellular processes. AA can be converted into biologically active compounds by metabolism by cyclooxygenases (COX). Beneficial effect of COX-2 inhibitor celecoxib add-on therapy has been reported in early stage of schizophrenia. Moreover, add-on treatment of celecoxib attenuated refractory depression and bipolar depression. Further, the COX/prostaglandin E pathway play an important role in synaptic plasticity and may be included in pathophysiology in autism spectrum disorders (ASD). In this regard, plasma transferrin, which is an iron mediator related to eicosanoid signaling, may be related to social impairment of ASD. COX-2 is typically induced by inflammatory stimuli in the majority of tissues, and the only isoform responsible for propagating the inflammatory response. Thus, COX-2 inhibitors considered as the best target for Alzheimer’s disease.


Neuroscience Letters | 2016

Down-regulation of a signaling mediator in association with lowered plasma arachidonic acid levels in individuals with autism spectrum disorders

Kunio Yui; George Imataka; Yohei Kawasaki; Hiroshi Yamada

Previous studies have indicated that the altered composition of polyunsaturated fatty acids (PUFAs) might contribute to the pathophysiology of autism spectrum disorder (ASD). We examined the relationship between the plasma fatty acid levels, expressed as μg/ml, and the plasma levels of biomarkers of AA-related signaling mediators, such as ceruloplasmin, transferrin and superoxide dismutase, and assessed the behavioral symptoms of 30 individuals with ASD (mean age, 13.6 ± 4.3 years old) compared with 20 age- and gender-matched normal controls (mean age, 13.2 ± 5.4 years old) using Aberrant Behavior Checklists (ABC). The plasma levels of EPA and the plasma ratios of EPA/AA were significantly higher, while the plasma levels of AA and metabolites, such as 5,8,11,14-eicosatetraenoic acid, adrenic acid, and ceruloplasmin (Cp), were significantly lower in the 30 individuals with ASD compared with the 20 normal controls. The ABC scores were significantly increased in the ASD group compared with those of the control group. Thus, the results of the present study revealed that reduced plasma levels of AA and metabolites in association with high plasma EPA/AA ratios might down-regulate AA-related signaling mediators, such as Cp. Subsequently, reduced plasma Cp levels might reduce the protective capacity for brain damage, resulting in the pathophysiology underlying the behavioral symptoms in individuals with ASD. These findings suggest that reduced plasma AA levels may downregulate Cp.


Pediatric Neurology | 2003

Reversible altered consciousness with brain atrophy caused by valproic acid.

Hideo Yamanouchi; Takako Ota; George Imataka; Eiji Nakagawa; Mitsuoki Eguchi

A 5-year-old female developed alteration of consciousness during 3 days of long-term treatment with valproic acid for localization-related epilepsy. Computed tomography revealed cerebral atrophy, and electroencephalography presented slow background activity. Consciousness cleared only 12 hours after valproic acid was discontinued, and normal electroencephalography results were evident 1 week later. Cerebral atrophy was nonexistent 2 months later. This rapidly developing but reversible alteration of consciousness in parallel with brain atrophy is recognized as a rare idiosyncratic adverse effect of valproic acid.


Journal of Child Neurology | 2002

Congenital Bilateral Perisylvian Syndrome Associated With Congenital Constriction Band Syndrome

Hideo Yamanouchi; Takako Ota; George Imataka; Yuri Hagiwara; Eiji Nakagawa; Mitsuoki Eguchi

We report a 7-year-old boy with congenital bilateral perisylvian syndrome and congenital constriction band syndrome. The former is a congenital neurologic syndrome characterized by pseudobulbar palsy, mental retardation, epilepsy, and bilateral perisylvian polymicrogyria. The latter is a malformative disorder with digital ring constrictions and amputations, probably caused by early amnion rupture resulting in entanglement of fetal parts by amniotic strands. We believe that the combination of these two malformative disorders was not coincidental; instead, fetal circulatory disturbance related to chronic abruptio placentae could account for this combination. (J Child Neurol 2002;17:448-450).

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Osamu Arisaka

Dokkyo Medical University

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Hideo Yamanouchi

Saitama Medical University

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Keiko Tsukada

Dokkyo Medical University

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Masahiko Mitsui

Dokkyo Medical University

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