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Dive into the research topics where Yuhei Hamasaki is active.

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Featured researches published by Yuhei Hamasaki.


Brain & Development | 2010

Frequent association of autism spectrum disorder in patients with childhood onset epilepsy

Muneaki Matsuo; Toshiyuki Maeda; Kazuya Sasaki; Kiyohisa Ishii; Yuhei Hamasaki

Autism spectrum disorder (ASD) has a close relationship with epilepsy. This study retrospectively examined patients with epilepsy associated with ASD. Among the 519 patients with epilepsy, 79 patients (15.2%) had ASD. Sixty-two patients had idiopathic ASD and 17 had secondary ASD. The epilepsy patients with idiopathic ASD were retrospectively analyzed. There were 47 males and 15 females, ranging from 2 to 43 years of age (median 11 years). The most frequent age at the onset of seizures was 4 years, and 85% occurred before 10. ASD was detected after the onset of epilepsy in 29 cases (46.8%), and eight of them had been overlooked for more than five years. Most of these were high-functioning ASD cases. The most frequent type of seizure was a complex partial seizure (CPS; 68%). Paroxysmal activities on EEG were localized in the frontal area in about half of the cases. Multiple anti-epileptic drugs were used in 33.8% cases (two in 17.7%, three in 16.1%), and 67.3% of the patients were seizure-free for more than two years. An amelioration of the autistic symptoms occurred after epilepsy treatment in five cases (8%). CPS with frontal paroxysms occurring from one to nine years of age seems to be characteristic of epilepsy associated with ASD.


Pediatrics International | 2010

Japanese pediatric guidelines for the treatment and management of bronchial asthma 2008

Naomi Kondo; Toshiyuki Nishimuta; Sankei Nishima; Akihiro Morikawa; Yukoh Aihara; Toru Akasaka; Akira Akasawa; Yuichi Adachi; Hirokazu Arakawa; Takao Ikarashi; Toshiichi Ikebe; Toshishige Inoue; Tsutomu Iwata; Atsuo Urisu; Yukihiro Ohya; Kenji Okada; Hiroshi Odajima; Toshio Katsunuma; Makoto Kameda; Kazuyuki Kurihara; Yoichi Kohno; Tatsuo Sakamoto; Naoki Shimojo; Yutaka Suehiro; Kenichi Tokuyama; Mitsuhiko Nambu; Yuhei Hamasaki; Takao Fujisawa; Takehiko Matsui; Tomoyo Matsubara

The fourth version of the Japanese Pediatric Guidelines for the Treatment and Management of Bronchial Asthma 2008 (JPGL 2008) was published by the Japanese Society of Pediatric Allergy and Clinical Immunology in December 2008. In JPGL 2008, the recommendations were revised on the basis of the JPGL 2005. The JPGL 2008 is different to the Global Initiative for Asthma guideline in that it contains the following items: a classification system of asthma severity; recommendations for long‐term management organized by age; a special mention of infantile asthma; and an emphasis on prevention and early intervention. Here we show a summary of the JPGL 2008 revising our previous report concerning JPGL 2005.


Clinical Neuropathology | 2009

5-lipoxygenase pathway promotes cell proliferation in human glioma cell lines.

Ishii K; Masafumi Zaitsu; Yonemitsu N; Kan Y; Yuhei Hamasaki; Muneaki Matsuo

OBJECTIVE 5-lipoxygenase (5-LO) is a key enzyme in the synthesis of leukotrienes (LTs), that might promote carcinogenesis. We investigated 5-LO expression and examined whether the 5-LO pathway is associated with the proliferation of human brain tumors. METHODS We immunohistochemically evaluated the profile of 5-LO expression in various types of brain tumors obtained from 42 patients, and examined the proliferative effects of the 5-LO pathway in human glioma cell lines using a proliferation assay. RESULTS Immunohistochemistry of glioblastomas, astrocytomas, meningiomas, medulloblastomas, craniopharyngiomas, ependymomas, neurinomas, oligodendrogliomas, malignant lymphomas, dysembryoplastic neuroepithelial and metastatic brain tumors revealed 5-LO expression in the cytoplasm and nuclei or nuclear envelopes of tumor cells. The 5-LO inhibitor A861 and the LTA4 hydrolase inhibitor Bestatin dose-dependently suppressed the proliferation of A172 cells, a glioma cell line. CONCLUSIONS We confirmed the expression of 5-LO in various human brain tumors and demonstrated the partial suppression of tumor growth by inhibitors of the 5-LO-LTA4 hydrolase pathway in human glioma cell lines. The 5-LO-LTA4 pathway might play roles in the proliferation of human glioma cells.


Pediatric Neurology | 2002

Possible contribution of interferon-α to febrile seizures in influenza

Tatsuo Masuyama; Muneaki Matsuo; Tomohiro Ichimaru; Kiyohisa Ishii; Katsunori Tsuchiya; Yuhei Hamasaki

The systemic symptoms associated with influenza infection are mainly attributable to cytokines. To elucidate whether the high incidence of creatine kinase elevation and febrile seizures in influenza infection could be related to cytokines, we examined the serum levels of creatine kinase and cytokines (interferon-alpha, interleukin-6, and tumor necrosis factor-alpha) in patients with influenza and other febrile illness. Among those in the influenza group, 12 of 43 patients demonstrated elevated levels of creatine kinase (more than 200 IU/L), whereas in the control group two of 14 patients demonstrated elevated creatine kinase levels. When age was limited to under 7 years, seven of 32 patients (21.9%) in the influenza group had febrile seizures, whereas one of seven patients (14.3%) had a seizure in the control group. The influenza group demonstrated significantly high levels of interferon-alpha and interleukin-6. There was no correlation between cytokine levels and duration of fever or serum creatine kinase levels. The number of patients with high levels of interferon-alpha (>400 pg/mL) was significantly larger in the febrile seizure group than in the control group (six of seven patients in the febrile seizure group, 16 of 36 in the control group; P < 0.05). The present findings suggest the possible contribution of interferon-alpha in the pathogenesis of febrile seizures.


Annals of Allergy Asthma & Immunology | 2004

Regulatory mechanisms of Th2 cytokine–induced eotaxin-3 production in bronchial epithelial cells: possible role of interleukin 4 receptor and nuclear factor–κB

Ikuko Kobayashi; Shuichi Yamamoto; Natsuko Nishi; Kohsuke Tsuji; Miyoko Imayoshi; Shigeyasu Inada; Tomohiro Ichiamaru; Yuhei Hamasaki

BACKGROUND Several cytokine combinations have been shown to induce eotaxins in bronchial epithelium. The mechanism for differential regulation of eotaxin expression remains unclear. OBJECTIVE To investigate the regulatory mechanisms of eotaxin-3 production vs eotaxin-1 production in cultured bronchial epithelium. METHODS Messenger RNA (mRNA) expression levels of eotaxin-1, eotaxin-2, and eotaxin-3 in a human bronchial epithelial cell line (BEAS-2B) and a normal human bronchial epithelial cell were examined using reverse transcriptase-polymerase chain reaction. Protein production was determined by enzyme-linked immunosorbent assay. Receptor expression was examined by flow cytometry. Phosphorylation of signal transducer and activator of transcription factor 6 (STAT6) was examined by immunoblotting. RESULTS Eotaxin-1 and eotaxin-3, but not eotaxin-2, mRNA expressions were induced by stimulation with interleukin (IL) 13 or IL-4. However, eotaxin-3 was the only protein detected after stimulation. A consistent 10-fold difference in the potency of IL-13- and IL-4-mediated induction of eotaxin-3 mRNA expression was observed. Interleukin 4 induced more potent induction of STAT6 phosphorylation compared with IL-13. The BEAS-2B cells were observed to express types 1 and 2 IL-4 receptors. Pretreatment with tumor necrosis factor a enhanced IL-4-induced eotaxin-1, but not eotaxin-3, mRNA expression. An inhibitor of nuclear factor-KB inhibited IL-13- and IL-4-induced eotaxin-1 gene expressions. However, it enhanced eotaxin-3 gene expression. CONCLUSIONS These results suggest that differences in the potency of IL-13- and IL-4-mediated induction of eotaxin-3 might be explained by expression of types 1 and 2 IL-4 receptors in bronchial epithelium. Differences in eotaxin-1 and eotaxin-3 mRNA and protein expression might be due to differential effects of nuclear factor-kappaB on gene expression.


Allergology International | 2014

Japanese Guideline for Childhood Asthma 2014

Yuhei Hamasaki; Yoichi Kohno; Naomi Kondo; Sankei Nishima; Toshiyuki Nishimuta; Akihiro Morikawa

The Japanese Guideline for the Diagnosis and Treatment of Allergic Diseases 2013 (JAGL 2013) describes childhood asthma after the Japanese Pediatric Guideline for the Treatment and Management of Asthma 2012 (JPGL 2012) by the Japanese Society of Pediatric Allergy and Clinical Immunology. JAGL 2013 provides information on diagnosis by age group from infancy to puberty (0-15 years of age), treatment for acute exacerbations, long-term management by anti-inflammatory drugs, daily life guidance, and patient education to allow non-specialist physicians to refer to this guideline for routine medical treatment. JAGL differs from the Global Initiative for Asthma Guideline (GINA) in that JAGL emphasizes early diagnosis and intervention at <2 years and 2-5 years of age. A management method, including step-up or step-down of long-term management drugs based on the status of asthma control levels, as in JAGL, is easy to understand, and thus the Guideline is suitable as a frame of reference for routine medical treatment. JAGL has also introduced treatment and management using a control test on children, recommending that the physician aim at complete control by avoiding exacerbation factors and by appropriate use of anti-inflammatory drugs.The Japanese Guideline for the Diagnosis and Treatment of Allergic Diseases 2013 (JAGL 2013) describes childhood asthma after the Japanese Pediatric Guideline for the Treatment and Management of Asthma 2012 (JPGL 2012) by the Japanese Society of Pediatric Allergy and Clinical Immunology. JAGL 2013 provides information on diagnosis by age group from infancy to puberty (0-15 years of age), treatment for acute exacerbations, long-term management by anti-inflammatory drugs, daily life guidance, and patient education to allow non-specialist physicians to refer to this guideline for routine medical treatment. JAGL differs from the Global Initiative for Asthma Guideline (GINA) in that JAGL emphasizes early diagnosis and intervention at <2 years and 2-5 years of age. A management method, including step-up or step-down of long-term management drugs based on the status of asthma control levels, as in JAGL, is easy to understand, and thus the Guideline is suitable as a frame of reference for routine medical treatment. JAGL has also introduced treatment and management using a control test on children, recommending that the physician aim at complete control by avoiding exacerbation factors and by appropriate use of anti-inflammatory drugs.


Journal of Pediatric Hematology Oncology | 1986

Factor VIII concentrate-responsive thrombocytopenia, hemolytic anemia, and nephropathy: evidence that factor VIII:von Willebrand factor is involved in its pathogenesis

Toshiro Hara; Akiko Kitano; Toshikazu Kajiwara; Tsutomu Kondo; Kazuhiro Sakai; Yuhei Hamasaki

A 4-year-old Japanese girl had a congenital disorder that was characterized by recurrent thrombocytopenia, hemolytic anemia, hematuria, and proteinuria, which were repeatedly improved by the infusion of factor VIII concentrate. She developed the similar symptoms within 1 h after 1-desamino-8-D-arginine vasopressin (DDAVP) administration. Coagulation studies 30 and 60 min after DDAVP infusion showed a disappearance of large factor VIII:von Willebrand factor (VIII:vWF) multimers, which was the same abnormality that was observed at acute episodes. There were no significant changes in the plasma levels of 6-keto-prostaglandin F1 alpha and thromboxane B2 before and after DDAVP infusion. These results provide further support that VIII:vWF is directly involved in the pathogenesis of this congenital disorder.


Pediatric Transplantation | 2005

Successful bone marrow transplantation in a patient with c‐mpl‐mutated congenital amegakaryocytic thrombocytopenia from a carrier donor

Kenji Muraoka; Eiichi Ishii; Kenji Ihara; Miyoko Imayoshi; Sumio Miyazaki; Toshiro Hara; Yuhei Hamasaki

Abstract:  Congenital amegakaryocytic thrombocytopenia (CAMT) is characterized by severe thrombocytopenia and the absence of megakaryocytes in bone marrow. Furthermore, mutation of the c‐mpl gene has been identified as a cause of this disorder. The only curative treatment is allogeneic stem cell transplantation (SCT). The current report describes a patient exhibiting c‐mpl mutation in both alleles who underwent transplantation of allogeneic bone marrow donated by her brother, a c‐mpl mutated carrier, employing a fludarabine‐based conditioning regimen. Engraftment and reconstitution of hematopoietic cells was rapid and without complications. These findings suggest that the carrier donor displaying the c‐mpl mutation can serve as a donor source for SCT.


Genetics in Medicine | 2014

Comprehensive and quantitative multilocus methylation analysis reveals the susceptibility of specific imprinted differentially methylated regions to aberrant methylation in Beckwith-Wiedemann syndrome with epimutations

Toshiyuki Maeda; Ken Higashimoto; Kosuke Jozaki; Hitomi Yatsuki; Kazuhiko Nakabayashi; Yoshio Makita; Hidefumi Tonoki; Nobuhiko Okamoto; Fumio Takada; Hirofumi Ohashi; Makoto Migita; Rika Kosaki; Keiko Matsubara; Tsutomu Ogata; Muneaki Matsuo; Yuhei Hamasaki; Yasufumi Ohtsuka; Kenichi Nishioka; Keiichiro Joh; Tsunehiro Mukai; Kenichiro Hata; Hidenobu Soejima

Purpose:Expression of imprinted genes is regulated by DNA methylation of differentially methylated regions (DMRs). Beckwith–Wiedemann syndrome is an imprinting disorder caused by epimutations of DMRs at 11p15.5. To date, multiple methylation defects have been reported in Beckwith–Wiedemann syndrome patients with epimutations; however, limited numbers of DMRs have been analyzed. The susceptibility of DMRs to aberrant methylation, alteration of gene expression due to aberrant methylation, and causative factors for multiple methylation defects remain undetermined.Methods:Comprehensive methylation analysis with two quantitative methods, matrix-assisted laser desorption/ionization mass spectrometry and bisulfite pyrosequencing, was conducted across 29 DMRs in 54 Beckwith–Wiedemann syndrome patients with epimutations. Allelic expressions of three genes with aberrant methylation were analyzed. All DMRs with aberrant methylation were sequenced.Results:Thirty-four percent of KvDMR1–loss of methylation patients and 30% of H19DMR–gain of methylation patients showed multiple methylation defects. Maternally methylated DMRs were susceptible to aberrant hypomethylation in KvDMR1–loss of methylation patients. Biallelic expression of the genes was associated with aberrant methylation. Cis-acting pathological variations were not found in any aberrantly methylated DMR.Conclusion:Maternally methylated DMRs may be vulnerable to DNA demethylation during the preimplantation stage, when hypomethylation of KvDMR1 occurs, and aberrant methylation of DMRs affects imprinted gene expression. Cis-acting variations of the DMRs are not involved in the multiple methylation defects.Genet Med 16 12, 903–912.


Annals of Allergy Asthma & Immunology | 2005

Squamous cell carcinoma-related antigen in children with acute asthma

Natsuko Nishi; Michiko Miyazaki; Kosuke Tsuji; Tomohiro Hitomi; Eriko Muro; Masafumi Zaitsu; Syuichi Yamamoto; Shigeyasu Inada; Ikuko Kobayashi; Tomohiro Ichimaru; Kenji Izuhara; Fumio Nagumo; Noriko Yuyama; Yuhei Hamasaki

BACKGROUND Increased serum levels of squamous cell carcinoma-related antigen (SCCA) have been observed in patients with allergic disorders, such as atopic dermatitis and bronchial asthma. T(H)2 cytokines, which are known to be involved in the pathogenesis of allergic disorders, stimulate new synthesis of SCCA in cultured human airway epithelial cells. OBJECTIVE To investigate whether SCCA levels increase during acute exacerbations of asthma in children and whether the T(H)2 cytokines, interleukin 4 (IL-4) and IL-13, are associated with SCCA levels. METHODS Serum levels of SCCA, IL-4, and IL-13 were measured by enzyme immunoassay during the acute phase of an asthma exacerbation (on hospital admission) and in the recovery phase (after symptoms had subsided). RESULTS In the 35 children who participated in this study, serum levels of SCCA were significantly elevated in the acute phase (mean +/- SD, 3.09 +/- 2.03 ng/mL) compared with the recovery phase (mean +/- SD, 1.47 +/- 0.64 ng/mL) of an asthma exacerbation (P < .001). In 12 children, the IL-13 levels were observed to correlate with SCCA levels during the recovery phase (r = 0.68, P = .02) but not during the acute phase of an asthma exacerbation. CONCLUSIONS Serum SCCA levels increase during the acute phase of an asthma exacerbation. During this phase, the increased synthesis of SCCA is not associated with IL-13 but rather mediated by other undefined stimuli. IL-13 may contribute to the basal production of SCCA in asthmatic children.

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