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Dive into the research topics where Katsuya Yamamoto is active.

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Featured researches published by Katsuya Yamamoto.


European Journal of Paediatric Neurology | 1997

Acute encephalopathy with bilateral striatal necrosis: favourable response to corticosteroid therapy

Katsuya Yamamoto; Hiroo Chiba; Mamiko Ishitobi; Hiroshi Nakagawa; Tatsuji Ogawa; Kiyoshi Ishii

A case of acute encephalopathy with selective bilateral symmetrical striatal lesions is reported. The patient was a previously healthy 4-year-old boy who became obtunded after a febrile illness and fell into a state of delirium with severe pain in the feet. He showed abnormal postures: hyperextension of the neck and upper limbs and extreme flexion of both lower limbs, and abnormal involuntary movements of the limbs: tremor, athetotic movement and right hemiballismus. Analysis of serum antibody titres suggested recent primary infection of herpes simplex type 1 (HSV-1). Cranial T2-weighted magnetic resonance imaging (MRI) demonstrated areas of high-signal intensity involving the whole basal ganglia bilaterally. He showed rapid clinical improvement after the initiation of corticosteroid therapy; complete clinical recovery was noted 3 months after the onset. Serial MRI studies demonstrated a rapid reduction of the lesions, resulting in only slight T2-hyperintense areas in both caudate nuclei. The pathogenesis of the disorder remains unknown, though an autoimmune mechanism has been speculated. The clinical and laboratory findings in this case suggested a possible role of HSV-1 in the pathomechanism of the disorder and a beneficial effect of early corticosteroid therapy.


Pediatrics International | 1996

Acute disseminated encephalomyelitis associated with Mycoplasma pneumoniae infection.

Katsuya Yamamoto; Masaru Takayanagi; Yasushi Yoshihara; Yuji Murata; Seiichi Kato; Masatoshi Otake; Hiroshi Nakagawa

An 8 year old girl with acute disseminated encephalomyelitis (ADEM) is described. Elevated serum antibody titers suggested recent Mycoplasma pneumoniae infection. T2‐weighted image of magnetic resonance imaging (MRI) disclosed multiple lesions of high signal intensity in bilateral basal ganglia and thalami as well as in the white matter. Postcontrast T1‐weighted image revealed an enhanced lesion in the deep white matter. She showed rapid clinical improvement in response to corticosteroid therapy. The lesions had disappeared completely on MRI performed 10 weeks after the onset. ADEM is believed to be a demyelinating disorder of probable autoimmune etiology. MRI findings in this case may support the hypothesis that the primary pathological event is vascular injury and demyelination occurs only as a secondary phenomenon.


NeuroImage | 2005

Opercular to interhemispheric source distribution of benign rolandic spikes of childhood

Mamiko Ishitobi; Nobukazu Nakasato; Katsuya Yamamoto; Kazuie Iinuma

We evaluated the source distribution of benign rolandic spikes of childhood along and across the central sulcus in 15 patients, aged between 7 and 15 years, who suffered from seizure disorders. Previous routine EEG showed centrotemporal spikes, but none of them had major abnormalities on brain magnetic resonance imaging or neurological deficits. The equivalent current dipoles (ECDs) of the spikes measured by whole-head magnetoencephalography (MEG) were compared to the spike distributions detected by simultaneous scalp EEG according to the international 10-20 system. Locations and orientations of the MEG spikes corresponded to the EEG spike distribution as follows: superiorly oriented spike MEG dipoles in the opercular area corresponded to T3/4 negative peaks (8 spike groups in 6 patients); anteriorly oriented spike dipoles in the rolandic area corresponded to C3/4 or P3/4 negative peaks (17 spike groups in 13 patients); laterally oriented spike dipoles in the interhemispheric area corresponded to Cz/Pz negative peaks (4 spike groups in 3 patients); and others (4 spike groups in 4 patients). Rolandic spikes include three main types according to the ECD location from the opercular to the interhemispheric areas. The functional anatomy of benign rolandic spikes was correlated with partial seizure semiology. All three rolandic spike types can be explained by a precentral origin, assuming that the surface negative potential is continuous from the gyral to fissural cortices.


Journal of the Neurological Sciences | 2009

Efficacy of idebenone for respiratory failure in a patient with Leigh syndrome: A long-term follow-up study

Kazuhiro Haginoya; Shigeaki Miyabayashi; Masahiro Kikuchi; Akira Kojima; Katsuya Yamamoto; Kiyoshi Omura; Mitsugu Uematsu; Naomi Hino-Fukuyo; Soichiro Tanaka; Shigeru Tsuchiya

Respiratory failure can be the direct cause of death in patients with Leigh syndrome. Unfortunately, no effective treatment strategy is available. Here, we report successful treatment of a patient with Leigh syndrome using idebenone, a derivative of coenzyme Q-10. The patients brainstem function, especially respiratory function, improved after idebenone treatment. Idebenone may be worth trying in patients with Leigh syndrome.


Epilepsy Research | 2009

Reduced levels of interleukin-1 receptor antagonist in the cerebrospinal fluid in patients with West syndrome.

Kazuhiro Haginoya; Rie Noguchi; Yajuan Zhao; Mitsutoshi Munakata; Hiroyuki Yokoyama; Soichiro Tanaka; Naomi Hino-Fukuyo; Mitsugu Uematsu; Katsuya Yamamoto; Masaru Takayanagi; Kazuie Iinuma; Shigeru Tsuchiya

We measured the levels of pro- and anti-inflammatory cytokines in the cerebrospinal fluid (CSF) of 24 patients with West syndrome to clarify whether inflammatory cytokines were involved in the pathophysiology of West syndrome. There was no significant elevation of any of the three pro-inflammatory cytokines, interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha, in patients with West syndrome as compared with those in controls. However, level of anti-inflammatory cytokine, IL-1 receptor antagonist was significantly decreased in the CSF of patients with West syndrome. Further study is needed to elucidate whether an immune system disturbance is involved in the pathophysiology of West syndrome.


Journal of Pediatric Gastroenterology and Nutrition | 1990

CHRONIC PANCREATITIS IN MUSCULAR CYTOCHROME C OXIDASE DEFICIENCY

Seiichi Kato; Shigeaki Miyabayashi; Ryoji Ohi; Hiroshi Nakagawa; Jun-ichiro Abe; Katsuya Yamamoto; Shuichi Watanabe; Keiya Tada

Chronic pancreatitis is described in a 10-year-old boy with mitochondrial myopathy due to cytochrome c oxidase (complex IV) deficiency. There have been few reports of chronic pancreatitis associated with congenital metabolic diseases. Marked pancreatic calcifications and pseudocysts of the pancreatic head and tail were demonstrated by computed tomography of the abdomen and by endoscopic retrograde pancreatography, which were thought to be useful methods for morphological examination of the pancreas. In the patient, no possible etiological factors were identified, including anomalous pancreatobiliary ductal junction or biochemical abnormalities. The association between cytochrome c oxidase deficiency and chronic pancreatitis remains to be established.


Brain & Development | 2002

Two successful cases of bromide therapy for refractory symptomatic localization-related epilepsy

Masaru Takayanagi; Katsuya Yamamoto; Hiroshi Nakagawa; Mitsutoshi Munakata; Rie Kato; Hiroyuki Yokoyama; Kazuhiro Haginoya; Kazuie Iinuma

Potassium bromide was tried for two children with daily convulsive focal motor seizures with unconsciousness and focal motor seizure status. The treatment resulted in complete cessation of the attacks. It has been reported that bromide is effective for generalized tonic-clonic seizures and not for complex partial seizures, such as convulsive focal motor seizures with unconsciousness. However, our experiences provide evidence that bromide is one of the useful therapeutic agents for intractable symptomatic localization-related epilepsy.


Journal of Child Neurology | 1992

Acute Transverse Myelitis in a 15-month-old Girl: Report of a Case With MRI Findings:

Katsuya Yamamoto; Hiroshi Nakagawa; Seiichi Kato; Jun-ichiro Abe; Shigeo Inoue; Hidenori Shibuya

A 15-month-old girl demonstrated progressive weakness in all limbs. Magnetic resonance imaging (MRI) on admission revealed (1) diffuse and symmetric cervical cord swelling, (2) diffuse decrease and increase in signal intensity within the affected cord on T1- and T2-weighted images, respectively, (3) preserved anatomic structure of gray and white matter of the cord, and (4) lack of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhancing effect. She showed rapid clinical improvement in response to steroid therapy, and repeat MRI showed marked reduction in the degree of cord swelling and abnormal signal intensity. Based on the above clinical and MRI findings, the diagnosis of acute transverse myelitis was made. Although various pathologic conditions also could produce similar cord swelling and abnormal signal intensity on MRI, the third and fourth findings mentioned above suggested that the lesion was inflammatory rather than neoplastic. Our case indicates that MRI may be informative in differentiating acute transverse myelitis from other intramedullary disorders. (J Child Neurol 1992;7:208-212).


Journal of the Neurological Sciences | 2015

Elevated serum levels of neutrophil elastase in patients with influenza virus-associated encephalopathy

Guilian Sun; Chiharu Ota; Setsuko Kitaoka; Yoko Chiba; Masaru Takayanagi; Taro Kitamura; Katsuya Yamamoto; Hiromi Fujie; Hitoshi Mikami; Mitsugu Uematsu; Naomi Hino-Fukuyo; Mitsutoshi Munakata; Shigeo Kure; Kazuhiro Haginoya

We examined serum levels of various cytokines, chemokines, growth factors, and adhesion molecules in patients with uncomplicated influenza (n=20) and influenza virus-associated encephalopathy (IE) (n=18) to understand the underlying mechanism of IE. We found that IL-1β, IL-2, IL-5, IL-6, IL-7, IL-8, IL-10, IL-13, G-CSF, GM-CSF, TNF-α, TIMP-1, MMP-9, sE-selectin, and neutrophil elastase were elevated significantly in sera from patients with uncomplicated influenza and those with IE, compared with normal controls (n=20). Of note, neutrophil elastase, sE-selectin, IL-8, and IL-13 were elevated significantly in IE as compared with uncomplicated influenza. In the present study, for the first time, we found that serum levels of neutrophil elastase were increased in patients with IE compared with uncomplicated influenza, which suggested that cerebral endothelial damage in the development of IE was mediated by neutrophil elastase. The present study implied that anti-elastase agents are possibly an effective therapeutic protocol for IE, but this needs further elucidation.


Journal of Neurology | 1991

Dystrophin immunohistochemistry in a symptomatic carrier of becker muscular dystrophy

Kazuhiro Haginoya; Katsuya Yamamoto; Kazuie Iinuma; Toshiro Yanagisawa; Yu Ichinohasama; Michie Shimmoto; Yoshiyuki Suzuki; Keiya Tada

SummaryImmunohistochemical localization of dystrophin was studied in a symptomatic carrier of Becker muscular dystrophy (BMD). Muscle biopsy specimens from a female carrier showed findings compatible with slowly progressive muscular dystrophy by ordinary histochemical examinations. Immunohistochemical study, using an antiserum raised against a synthetic peptide fragment of dystrophin, demonstrated a mixture of staining patterns, including continuous but faint positive fibres, partially disrupted fibres and negative fibres. These findings were identical to those of patients with BMD and appear to differ from previous findings in female carriers of Duchenne muscular dystrophy. This report is the first immunohistochemical study of a symptomatic female proven by molecular genetic analysis to be a carrier of BMD.

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Hiroshi Nakagawa

University of Pennsylvania

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