Updated on 2025/08/22

写真a

 
YAMAMOTO Masaki
 
Organization
School of Medicine Department of Pediatrics Associate Professor
Title
Associate Professor
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Research Interests

  • hematopoietic stem cell transplantation

  • luekemia

  • GVHD

  • pediatric cancer

Research Areas

  • Life Science / Embryonic medicine and pediatrics  / 小児血液学

Professional Memberships

  • THE JAPANESE SOCIETY OF HEMATOLOGY

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  • JAPAN PEDIATRIC SOCIETY

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  • 日本造血細胞移植学会

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  • THE JAPANESE SOCIETY OF PEDIATRIC HEMATOLOGY / ONCOLOGY

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Papers

  • Crizotinib therapy for congenital embryonal rhabdomyosarcoma associated with an <i>ATIC–ALK</i> gene fusion

    Yusuke Akane, Masaki Yamamoto, Akira Takebayashi, Ryo Hamada, Keita Igarashi, Makoto Emori, Shintaro Sugita, Kohichi Takada, Tadashi Hasegawa, Takeshi Tsugawa

    Pediatric Blood &amp; Cancer   2024.6

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    Publishing type:Research paper (scientific journal)   Publisher:Wiley  

    DOI: 10.1002/pbc.31148

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  • Children’s cognition and attitudes during long-term cancer treatment: an ethnographic study

    Ryoko Michinobu, Masaki Yamamoto, Keita Igarashi, Yoshiyuki Sakai, Yusuke Akane, Dai Yamamoto, Akira Takebayashi, Takahiro Mikami, Hiroyuki Tsutsumi, Takeshi Tsugawa

    BMJ Paediatrics Open   2024.4

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    DOI: 10.1136/bmjpo-2023-002405

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  • Parental Decision-Making in Cancer Therapy: A Long-Term Observational Study. International journal

    Ryoko Michinobu, Masaki Yamamoto, Yoshiyuki Sakai, Takahiro Mikami, Keita Igarashi, Kotoe Iesato, Akira Takebayashi, Tsukasa Hori, Hiroyuki Tsutsumi, Takeshi Tsugawa

    Clinical pediatrics   99228221150606 - 99228221150606   2023.1

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    Parental participation in shared decision-making in children's cancer therapy is essential because parents advocate for and support their children's wishes. However, little research has focused on this issue. We conducted a longitudinal observational study of 7 parents whose child had received their first cancer treatment. We recorded parents' behaviors, interactions, and narratives in 1 pediatric ward and 2 outpatient clinics. The recordings were systematically conducted and thematically analyzed using variable-oriented and process-oriented modes to assess the causal relationships among phenomena. We found 4 themes describing the processes by which parents developed and participated in shared decision-making. The first 2 themes reflected the development of reciprocal parental relationships and parent-other child relationships. These 2 types of relationship generated mutual trust and a sense of solidarity among parents (the third theme). This, in turn, became the foundation for parents to share decision-making with health care professionals (the fourth theme).

    DOI: 10.1177/00099228221150606

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  • Impact of BRAF/MEK inhibitor on BRAF V600E-mutated pilocytic astrocytoma. International journal

    Ryo Hamada, Yusuke Akane, Yukinori Akiyama, Kohichi Takada, Masaki Yamamoto

    Pediatrics international : official journal of the Japan Pediatric Society   65 ( 1 )   e15653   2023

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    DOI: 10.1111/ped.15653

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  • Children's decision making in cancer therapy: A long-term observational study. International journal

    Ryoko Michinobu, Masaki Yamamoto, Tsukasa Hori, Takahiro Mikami, Keita Igarashi, Kotoe Iesato, Akira Takebayashi, Takeshi Tsugawa, Yukihiko Kawasaki, Hiroyuki Tsutsumi

    Pediatrics international : official journal of the Japan Pediatric Society   2021.3

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    BACKGROUND: The survival rate of children with cancer has increased substantially in recent years. Shared decision making (i.e., the ability of children with cancer to express their will and share it with medical personnel) has become a particularly important issue. The nature and developmental processes of children's decision making in hospital should be understood. There is, however, a lack of research in this area. METHODS: From January 2016 to March 2018, we conducted a longitudinal qualitative observational study, within the context of medical anthropology, in a hospital pediatric ward in Japan. We investigated the nature and development of decision making among seven children aged 5-12 years with hematologic cancers. We recorded their everyday behaviors, interactions, narratives, and events in the ward. The recording was conducted systematically and thematically analyzed using both variable-oriented and process-oriented modes to assess causal relationships between the phenomena. RESULTS: The thematic analysis identified three thematic scenes in which children developed their will regarding cancer treatment: (1) adjusting to hospital life, (2) forming friendships with other children, and (3) communicating with medical personnel. Sharing information, building trusting relationships, and sharing treatment goals with medical personnel were identified as forms of children's participation in medical decision making. Through cultivated friendships, children's peer groups were sources of resilience and strength in overcoming difficulties in hospital life. CONCLUSIONS: The development of children's decision making in a pediatric oncology ward was based on various rich human relationships. Such relationships should be promoted to substantially improve shared decision making.

    DOI: 10.1111/ped.14700

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  • Multiple lung lesions in a 13-year-old girl with classical nodular sclerosis Hodgkin Lymphoma.

    Shuhei Adachi, Akira Takebayashi, Kotoe Iesato, Keita Igarashi, Masaki Yamamoto, Tsukasa Hori, Yukihiko Kawasaki, Taijiro Mishina, Shintaro Sugita

    International journal of hematology   113 ( 3 )   318 - 319   2021.3

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  • Familial Mediterranean Fever After Cord Blood Transplantation for Familial Hemophagocytic Lymphohistiocytosis. International journal

    Keita Igarashi, Tsukasa Hori, Masaki Yamamoto, Naoki Hatakeyama, Kotoe Iesato, Akira Takebayashi, Toshitaka Kizawa, Takako Miyamae, Manabu Kawamoto, Yukihiko Kawasaki

    Journal of pediatric hematology/oncology   2021.2

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    Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disorder accompanied by periodic fever and sterile serositis. We report a 5-year-old boy with FMF, who underwent second unrelated cord blood transplantation (CBT) for recurrent familial hemophagocytic lymphohistiocytosis. Periodic attacks of fever and abdominal pain started 6 months after CBT. He was diagnosed with FMF according to the Tel-Hashomer criteria and treated successfully with colchicine. Genetic testing showed heterozygous p.E148Q mutation in the MEFV gene from both donor and recipient cells. Several CBT-related factors including use of an immunosuppressant can potentially be involved in the pathogenesis of FMF in our patient.

    DOI: 10.1097/MPH.0000000000002081

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  • A SARS-CoV-2-positive patient coincidentally diagnosed with B-ALL. International journal

    Masaki Yamamoto, Yusuke Akane, Keita Igarashi, Tsukasa Hori, Yukihiko Kawasaki

    Pediatrics international : official journal of the Japan Pediatric Society   63 ( 2 )   221 - 223   2021.2

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    DOI: 10.1111/ped.14432

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  • An international retrospective study for tolerability of 6-mercaptopurine on NUDT15 bi-allelic variants in children with acute lymphoblastic leukemia. International journal

    Yoichi Tanaka, Allen Eng Juh Yeoh, Takaya Moriyama, Chi-Kong Li, Ko Kudo, Yuki Arakawa, Jassada Buaboonnam, Hui Zhang, Hsi-Che Liu, Hany Ariffin, Zhiwei Chen, Shirley K Y Kham, Rina Nishii, Daisuke Hasegawa, Junya Fujimura, Dai Keino, Kensuke Kondoh, Atsushi Sato, Takahiro Ueda, Masaki Yamamoto, Yuichi Taneyama, Moeko Hino, Masatoshi Takagi, Akira Ohara, Etsuro Ito, Katsuyoshi Koh, Hiroki Hori, Atsushi Manabe, Jun J Yang, Motohiro Kato

    Haematologica   106 ( 7 )   2026 - 2029   2021.1

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    Not available.

    DOI: 10.3324/haematol.2020.266320

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  • Correction: Reduced-intensity conditioning is effective for hematopoietic stem cell transplantation in young pediatric patients with Diamond-Blackfan anemia. International journal

    Shun Koyamaishi, Takuya Kamio, Akie Kobayashi, Tomohiko Sato, Ko Kudo, Shinya Sasaki, Rika Kanezaki, Daiichiro Hasegawa, Hideki Muramatsu, Yoshiyuki Takahashi, Yoji Sasahara, Hidefumi Hiramatsu, Harumi Kakuda, Miyuki Tanaka, Masataka Ishimura, Masanori Nishi, Akira Ishiguro, Hiromasa Yabe, Takeo Sarashina, Masaki Yamamoto, Yuki Yuza, Nobuyuki Hyakuna, Kenichi Yoshida, Hitoshi Kanno, Shouichi Ohga, Akira Ohara, Seiji Kojima, Satoru Miyano, Seishi Ogawa, Tsutomu Toki, Kiminori Terui, Etsuro Ito

    Bone marrow transplantation   56 ( 5 )   1218 - 1219   2020.10

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    An amendment to this paper has been published and can be accessed via a link at the top of the paper.

    DOI: 10.1038/s41409-020-01076-x

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  • Reduced-intensity conditioning is effective for hematopoietic stem cell transplantation in young pediatric patients with Diamond-Blackfan anemia. International journal

    Shun Koyamaishi, Takuya Kamio, Akie Kobayashi, Tomohiko Sato, Ko Kudo, Shinya Sasaki, Rika Kanezaki, Daiichiro Hasegawa, Hideki Muramatsu, Yoshiyuki Takahashi, Yoji Sasahara, Hidefumi Hiramatsu, Harumi Kakuda, Miyuki Tanaka, Masataka Ishimura, Masanori Nishi, Akira Ishiguro, Hiromasa Yabe, Takeo Sarashina, Masaki Yamamoto, Yuki Yuza, Nobuyuki Hyakuna, Kenichi Yoshida, Hitoshi Kanno, Shouichi Ohga, Akira Ohara, Seiji Kojima, Satoru Miyano, Seishi Ogawa, Tsutomu Toki, Kiminori Terui, Etsuro Ito

    Bone marrow transplantation   56 ( 5 )   1013 - 1020   2020.9

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    Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative therapy for the hematologic manifestations of Diamond-Blackfan anemia (DBA). However, data regarding the optimal conditioning regimen for DBA patients are limited. We retrospectively compared the outcomes of DBA patients who underwent HSCT using either myeloablative conditioning (MAC) or reduced-intensity conditioning (RIC) regimens. The patients belonged to a cohort treated at our hospitals between 2000 and 2018. HSCT was performed in 27 of 165 patients (16.4%). The median age at the time of HSCT was 3.6 years. Stem cell sources included bone marrow for 25 patients (HLA-matched sibling donors, n = 5; HLA-mismatched related donors, n = 2; HLA-matched/mismatched unrelated donors, n = 18) or cord blood for 2 patients. MAC or RIC regimens were used in 12 and 15 patients, respectively. Engraftment was successful in all 27 patients who underwent HSCT. Three patients who underwent HSCT using MAC regimens developed sinusoidal obstruction syndrome. The 3-year overall survival (OS) and failure-free survival rates (FFS) post-transplantations were 95.2% and 88.4%, respectively, with no significant differences between MAC and RIC regimens. Our data suggest that HSCTs using RIC regimens are effective and obtain engraftment with excellent OS and FFS for young DBA patients.

    DOI: 10.1038/s41409-020-01056-1

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  • Permanent insulin-dependent diabetes mellitus in a patient with acute lymphoblastic leukemia. International journal

    Yusuke Akane, Masaki Yamamoto, Keita Igarashi, Akira Takebayashi, Tsukasa Hori

    Pediatrics international : official journal of the Japan Pediatric Society   62 ( 3 )   403 - 405   2020.3

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    DOI: 10.1111/ped.14079

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  • 骨髄移植後の類洞閉塞症候群に対し生体肝移植を施行し救命しえた一例 Reviewed

    深澤 拓夢, 川村 典生, 市村 健太郎, 鈴木 琢士, 巖築 慶一, 財津 雅昭, 渡辺 正明, 藤好 真人, 長津 明久, 後藤 了一, 井口 晶裕, 五十嵐 敬太, 山本 雅樹, 神山 俊哉, 嶋村 剛, 武冨 紹信

    日本臨床外科学会雑誌   80 ( 12 )   2303 - 2303   2019.12

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  • Early Lymph Node Metastasis May Predict Poor Prognosis in Soft Tissue Sarcoma. International journal

    Makoto Emori, Hiroyuki Tsuchie, Hiroyuki Nagasawa, Tomoko Sonoda, Arihiko Tsukamoto, Junya Shimizu, Yasutaka Murahashi, Emi Mizushima, Kohichi Takada, Kazuyuki Murase, Kotoe Iesato, Keita Igarashi, Tsukasa Hori, Masaki Yamamoto, Shintaro Sugita, Naohisa Miyakoshi, Tadashi Hasegawa, Yoichi Shimada, Toshihiko Yamashita

    International journal of surgical oncology   2019   6708474 - 6708474   2019

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    Background: Lymph node metastasis (LNM) is a relatively rare event in soft tissue sarcoma. An association between the timing of LNM detection and patient prognosis is presently unknown. Patients and Methods: We retrospectively analyzed the clinicopathological features of 33 patients with LNM between 2001 and 2015. Analysis of the timing of LNM diagnosis was grouped according to patients presenting LNM in either <8 months (the median time from primary tumor diagnosis to LNM) or ≥8 months after primary tumor diagnosis. Results: A relationship between the primary tumor size and the timing of the LNM was not significantly found (Rs = 0.0088, p=0.96). Sixteen patients had an LNM detection duration of <8 months, and 17 patients had a duration of ≥8 months. The 5-year survival for patients with an LNM detection duration of <8 months and ≥8 months was 19% and 71%, respectively (p=0.0016). There were 19 patients with pulmonary metastases. Among them, there were 13 patients with a duration of primary tumor diagnosis to LNM of <8 months and 6 with a duration of ≥8 months (p=0.01). Conclusion: Early LNM (<8 months) may predict poor prognosis in soft tissue sarcoma.

    DOI: 10.1155/2019/6708474

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  • Vertebral canal invasion of cervical lipoblastoma in childhood: A case report

    Akira Takebayashi, Tsukasa Hori, Masaki Yamamoto, Kotoe Iesato, Keita Igarashi, Naoki Hatakeyama, Yukinori Akiyama, Masahiko Wanibuchi, Shintaro Sugita, Yoshiyuki Sakai, Minami Yoda, Hiroyuki Tsutsumi

    Iranian Journal of Pediatrics   28 ( 6 )   2018.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Kowsar Medical Publishing Company  

    DOI: 10.5812/ijp.68869

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  • Severe adverse events by tyrosine kinase inhibitors decrease survival rates in patients with newly diagnosed chronic-phase chronic myeloid leukemia. International journal

    Shuichi Ota, Toshihiro Matsukawa, Satoshi Yamamoto, Shinichi Ito, Motohiro Shindo, Kazuya Sato, Takeshi Kondo, Kyuhei Kohda, Hajime Sakai, Akio Mori, Tohru Takahashi, Hiroshi Ikeda, Hiroyuki Kuroda, Yoshihito Haseyama, Masaki Yamamoto, Takeo Sarashina, Makoto Yoshida, Ryoji Kobayashi, Mitsufumi Nishio, Toshimichi Ishihara, Yasuo Hirayama, Yasutaka Kakinoki, Hajime Kobayashi, Takashi Fukuhara, Masahiro Imamura, Mitsutoshi Kurosawa

    European journal of haematology   101 ( 1 )   95 - 105   2018.7

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    OBJECTIVE: This multicenter cooperative study aimed to analyze the adverse events (AEs) associated with tyrosine kinase inhibitors (TKIs) used as initial treatment for chronic-phase chronic myeloid leukemia (CML-CP) and their impact on outcome. METHODS: We retrospectively evaluated 450 patients with CML-CP who received TKIs between 2004 and 2014. RESULTS: The 5-year overall survival (OS) and event-free survival (EFS) rates were 95.1% and 89.0%, respectively. Patients with comorbidities (46.4%) and aged ≥60 years (50.4%) at diagnosis had significantly inferior OS to those without comorbidities and aged <60. Patients achieved higher rates of major molecular response (MMR) at 6 and 12 months after initial treatment with dasatinib or nilotinib compared to imatinib, but final MMR rates were almost the same. Sixty-six percent of patients required treatment modifications from first-line TKI therapy; the main reasons were AEs (48.4%) and failure (18%). Grade III-IV AEs in first-line TKI therapy were significantly correlated to inferior OS/EFS compared to grade 0-II AEs. CONCLUSION: Although long-term outcomes were similar in CML-CP patients treated with each TKI regardless of first-line TKI selection, severe AEs in first-line TKI therapy decreased their survival rates. Early change in TKIs is recommended, when faced with severe AEs of specific TKIs.

    DOI: 10.1111/ejh.13081

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  • Long-term prognosis of human herpesvirus 6 reactivation following allogeneic hematopoietic stem cell transplantation. International journal

    Kotoe Iesato, Tsukasa Hori, Yuko Yoto, Masaki Yamamoto, Natsuko Inazawa, Kenichi Kamo, Hiroshi Ikeda, Satoshi Iyama, Naoki Hatakeyama, Akihiro Iguchi, Junichi Sugita, Ryoji Kobayashi, Nobuhiro Suzuki, Hiroyuki Tsutsumi

    Pediatrics international : official journal of the Japan Pediatric Society   60 ( 6 )   547 - 552   2018.6

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    BACKGROUND: Patients undergoing hematopoietic stem cell transplantation (HSCT) frequently have HHV-6 reactivation typically during the early phase following HSCT. The long-term clinical complications and prognosis, however, remain unclear. METHODS: Between September 2010 and October 2012, whole blood samples from 105 patients collected weekly from prior to 6 weeks after HSCT underwent multiplex polymerase chain reaction (PCR) to screen for viral DNA, followed by real-time PCR for quantitative estimation. In 48 patients, only HHV-6 was detected in at least one sample. In 30 patients, no viral DNA was detected. Long-term clinical records were reviewed in March 2016. All 48 HHV-6-positive patients, and 24 patients in whom no viral DNA detected, were followed up. RESULTS: Median maximum HHV-6 DNA load in the blood of the HHV-6 reactivation group (n = 48) was 11 800 copies/μg peripheral blood leukocyte DNA (range, 52-310 000 000). Hemophagocytic syndrome (HPS) was diagnosed in two subjects with HHV-6 reactivation. Acute graft-versus-host disease (GVHD) developed more frequently in patients with HHV-6 reactivation than in patients without viral reactivation (P = 0.002), but there was no difference in incidence of chronic GVHD. There was no difference in engraftment of neutrophils and platelets between groups. There was also no difference in overall survival between groups. Onset of HPS, however, was associated with lower overall survival (P = 0.009). CONCLUSIONS: Human herpesvirus 6 reactivation was associated with acute GVHD, but not with chronic GVHD, engraftment or overall survival. Onset of HPS, however, predicts lower overall survival.

    DOI: 10.1111/ped.13551

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  • Non-alcoholic steatohepatitis induced by induction chemotherapy for pediatric acute lymphoblastic leukemia.

    Masaki Yamamoto, Tsukasa Hori, Keita Igarashi, Kotoe Iesato, Makoto Saito, Koji Miyanishi, Noriaki Kikuchi, Hiromi Fujita, Hiroyuki Tsutsumi

    International journal of hematology   107 ( 4 )   390 - 391   2018.4

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  • Predictive factors of response to IVIG in pediatric immune thrombocytopenic purpura. International journal

    Yukiko Higashide, Tsukasa Hori, Yuko Yoto, Hiroyuki Kabutoya, Saho Honjo, Yoshiyuki Sakai, Masanori Nojima, Minami Yoda, Masaki Yamamoto, Hiroyuki Tsutsumi

    Pediatrics international : official journal of the Japan Pediatric Society   60 ( 4 )   357 - 361   2018.4

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    BACKGROUND: Immune thrombocytopenic purpura (ITP) is commonly treated with i.v. immunoglobulin (IVIG). METHODS: We retrospectively evaluated whether pretreatment clinical and laboratory finding could predict the short- and long-term response to IVIG. RESULTS: Short-term response was estimated by platelet count 2 weeks after IVIG, and long-term response was assessed on thrombocytopenia-free survival (TFS). TFS was defined as the probability of survival without treatment failure after initial IVIG, such as relapse, requirement for additional therapeutic interventions, or progressing to chronic ITP. Seventy-six patients with newly diagnosed ITP who were initially treated with IVIG were evaluated. Fifty-three patients (69.7%) were determined as responders at 2 weeks after IVIG. On multivariate analysis, age ≥23 months (P = 0.020) and platelet count <9.0 × 109 /L (P = 0.018) were considered to be unfavorable factors for short-term response. Cumulative proportion of long-term (1 year) good prognosis was estimated at 53.0% (95%CI: 40.8-65.2). On multivariate analysis of unfavorable factors for long-term response, age ≥23 months (P = 0.020) was the only significant factor. CONCLUSIONS: For new-onset ITP in patients aged >2 years, corticosteroid therapy in addition to IVIG may be considered as the initial treatment.

    DOI: 10.1111/ped.13505

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  • Response to ponatinib before hematopoietic stem cell transplantation in a child with relapsed Philadelphia chromosome-positive acute lymphoblastic leukemia. International journal

    Masaki Yamamoto, Tsukasa Hori, Keita Igarashi, Hiroyuki Shimada, Hiroyuki Tsutsumi

    Pediatrics international : official journal of the Japan Pediatric Society   60 ( 1 )   85 - 87   2018.1

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    DOI: 10.1111/ped.13437

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  • Adrenocortical carcinoma characterized by gynecomastia: A case report.

    Takako Takeuchi, Yuko Yoto, Akira Ishii, Takeshi Tsugawa, Masaki Yamamoto, Tsukasa Hori, Hotaka Kamasaki, Kazutaka Nogami, Takanori Oda, Akihiro Nui, Sachiko Kimura, Takuya Yamagishi, Keiko Homma, Tomonobu Hasegawa, Maki Fukami, Yoko Watanabe, Hidehiko Sasamoto, Hiroyuki Tsutsumi

    Clinical pediatric endocrinology : case reports and clinical investigations : official journal of the Japanese Society for Pediatric Endocrinology   27 ( 1 )   9 - 18   2018

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    We present a 4-yr-old boy with adrenocortical carcinoma (ACC), diagnosed due to the appearance of gynecomastia as the presenting symptom. Six months prior to admission, an acute growth spurt along with the development of bilateral breast swelling was observed. He did not present any features of virilization, including enlargement of the testes, increase in testis volume, and penis size. Laboratory investigations showed gonadotropin-independent hypergonadism, with low LH/ FSH levels and elevated estradiol/testosterone levels. Abdominal computed tomography revealed a large heterogeneous mass adjacent to the right kidney and below the liver. Pathological investigations of the biopsy specimen demonstrated that the tumor was an ACC. Pre- and post-operative combination chemotherapy with mitotane was administered and surgical resection was carried out. Post-surgery, the elevated estradiol/testosterone concentrations reverted to within the reference range. Urinary steroid profile and tissue concentration analysis of estradiol and testosterone indicated the presence of estrogen in the ACC tissue. An investigation for TP53 gene aberrations revealed the presence of a germline point mutation in exon 4 (c.215C>G (p.Pro72Arg)). In ACC, the most common symptom is virilization, and feminization, characterized by gynecomastia, is very rare. However, a diagnostic possibility of ACC should be considered when we encounter patients who have developed gynecomastia without the influence of causative factors such as obesity or puberty, and do not present with the typical signs of virilization.

    DOI: 10.1297/cpe.27.9

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  • Virus reactivations after autologous hematopoietic stem cell transplantation detected by multiplex PCR assay. International journal

    Natsuko Inazawa, Tsukasa Hori, Masanori Nojima, Makoto Saito, Keita Igarashi, Masaki Yamamoto, Norio Shimizu, Yuko Yoto, Hiroyuki Tsutsumi

    Journal of medical virology   89 ( 2 )   358 - 362   2017.2

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    Several studies have indicated that viral reactivations following allogeneic hematopoietic stem cell transplantation (allo-HSCT) are frequent, but viral reactivations after autologous HSCT (auto-HSCT) have not been investigated in detail. We performed multiplex polymerase chain reaction (PCR) assay to examine multiple viral reactivations simultaneously in 24 patients undergoing auto-HSCT between September 2010 and December 2012. Weekly whole blood samples were collected from pre- to 42 days post-HSCT, and tested for the following 13 viruses; herpes simplex virus 1 (HSV-1), HSV-2, varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), HHV-7, HHV-8, adeno virus (ADV), BK virus (BKV), JC virus (JCV), parvovirus B19 (B19V), and hepatitis B virus (HBV).  Fifteen (63%) patients had at least one type of viral reactivation. HHV6 (n = 10; 41.7%) was most frequently detected followed by EBV (n = 7; 29.2%). HHV-6 peaked on day 21 after HSCT and promptly declined. In addition, HBV, CMV, HHV7, and B19V were each detected in one patient. HHV6 reactivation was detected in almost half the auto-HSCT patients, which was similar to the incidence in allo-HSCT patients. The incidence of EBV was unexpectedly high. Viral infections in patients undergoing auto-HSCT were higher than previously reported in other studies. Although there were no particular complications of viral infection, we should pay attention to possible viral reactivations in auto-HSCT patients. J. Med. Virol. 89:358-362, 2017. © 2016 Wiley Periodicals, Inc.

    DOI: 10.1002/jmv.24621

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  • HHV-6 encephalitis may complicate the early phase after allogeneic hematopoietic stem cell transplantation: Detection by qualitative multiplex PCR and subsequent quantitative real-time PCR. International journal

    Natsuko Inazawa, Tsukasa Hori, Masaki Yamamoto, Naoki Hatakeyama, Yuko Yoto, Masanori Nojima, Hiroshi Yasui, Nobuhiro Suzuki, Norio Shimizu, Hiroyuki Tsutsumi

    Journal of medical virology   88 ( 2 )   319 - 23   2016.2

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    Viral reactivation following hematopoietic stem cell transplantation (HSCT) can cause various complications especially viral encephalitis. In this prospective study, we investigated the correlation of post-HSCT viral reactivation in blood with CNS dysfunction. We employed a multiplex PCR that detects 13 kinds of viruses as a first-line screening test and real-time PCR for subsequent quantitative evaluation. Five hundred ninety-one whole blood samples were collected from 105 patients from before until 42 days after HSCT. Seven patients developed CNS dysfunction such as altered consciousness. In six of the seven, the multiplex PCR test detected HHV-6 DNA in at least one sample. In contrast, DNA from other viruses, such as CMV, EBV, HHV-7, adenovirus, and HBV was never detected in any of the seven patients throughout the study period. Quantitative measurement of whole blood HHV-6 DNA levels demonstrated four of the six HHV-6 DNA loads were elevated at successive time points during the CNS dysfunction. In addition, the virus DNA peaks were temporally associated with the development of CNS dysfunction. CSF was tested in two of the four patients and high HHV-6 DNA levels comparable to those in whole blood were confirmed in both. These four patients were, thus, suspected to have developed HHV-6 encephalitis, a rate of 3.8% in the study population. Our results suggest that early diagnosis of probable HHV-6 encephalitis can be improved by confirming high HHV-6 DNA load in blood.

    DOI: 10.1002/jmv.24340

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  • Large-scale multiplex polymerase chain reaction assay for diagnosis of viral reactivations after allogeneic hematopoietic stem cell transplantation. International journal

    Natsuko Inazawa, Tsukasa Hori, Naoki Hatakeyama, Masaki Yamamoto, Yuko Yoto, Masanori Nojima, Nobuhiro Suzuki, Norio Shimizu, Hiroyuki Tsutsumi

    Journal of medical virology   87 ( 8 )   1427 - 35   2015.8

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    Viral reactivations following hematopoietic stem cell transplantation are thought to result from the breakdown of both cell-mediated and humoral immunity. As a result, many viruses could be reactivated individually or simultaneously. Using a multiplex polymerase chain reaction (PCR), we prospectively examined many kinds of viral DNAs at a time in 105 patients who underwent allogeneic hematopoietic stem cell transplantation. In total, 591 whole blood samples were collected weekly from pre- to 42 days post-transplantation and the following 13 viruses were tested; herpes simplex virus 1 (HSV-1), HSV-2, varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpes virus 6 (HHV-6), HHV-7, HHV-8, adenovirus, BK virus (BKV), JC virus (JCV), parvovirus B19, and hepatitis B virus (HBV). Several viral DNAs were detected in 12 patients before hematopoietic stem cell transplantation. The detection rate gradually increased after transplantation and peaked at 21 days. The most frequently detected virus was HHV-6 (n = 63; 60.0%), followed by EBV (n = 11; 10.5%), CMV (n = 11; 10.5%), and HHV-7 (n = 9; 8.6%). Adenovirus and HBV were each detected in one patient (1.0%). Detection of HHV-6 DNA was significantly more common among patients undergoing cord blood transplantation or with steroid treatment. EBV DNA tended to be more common in patients treated with anti-thymocyte globulin. Multiplex PCR was useful for detecting many viral reactivations after hematopoietic stem cell transplantation, simultaneously. Cord blood transplantation, steroid treatment, or anti-thymocyte globulin use was confirmed to be risk factors after transplantation.

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  • Extramedullary Tumor of Cerebral Falx: An Unusual Presentation of Acute Megakaryocytic Leukemia. International journal

    Naoki Hatakeyama, Tsukasa Hori, Masaki Yamamoto, Keita Igarashi, Kotoe Iesato, Akira Takebayashi, Makoto Kaneda, Takeo Sarashina, Naohisa Toriumi, Hiroyuki Tsutsumi

    Journal of pediatric hematology/oncology   37 ( 3 )   e170-2   2015.4

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    In childhood acute myelogenous leukemia, extramedullary tumor is an occasional clinical symptom. However, extramedullary acute megakaryocytic leukemia is extremely rare. Here, we report an extremely rare case of acute megakaryocytic leukemia in a patient who presented with extramedullary tumor of cerebral falx as a first manifestation before the diagnosis of systemic bone marrow leukemia.

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  • Multiplex PCR for Virus Infections after Allogeneic Hematopoietic Stem Cell Transplantation Reviewed

    Natsuko Inazawa, Tsukasa Hori, Masaki Yamamoto, Keita Igarashi, Hiroyuki Tsutsumi, Masanori Nojima, Nobuhiro Suzuki, Norio Shimizu, Naoki Hatakeyama

    BLOOD   124 ( 21 )   2014.12

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  • Cushing's disease developing independently from acute lymphoblastic leukemia. International journal

    Masaki Yamamoto, Tsukasa Hori, Naoki Hatakeyama, Keita Igarashi, Hotaka Kamasaki, Takako Takeuchi, Yoshihiro Minamida, Masahiko Wanibuchi, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    Indian journal of pediatrics   81 ( 9 )   952 - 4   2014.9

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  • Use of recombinant thrombomodulin in disseminated intravascular coagulation complicated hemophagocytic lymphohistiocytosis. International journal

    Masaki Yamamoto, Tsukasa Hori, Naoki Hatakeyama, Keita Igarashi, Natsuko Inazawa, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    Indian journal of pediatrics   81 ( 3 )   288 - 91   2014.3

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    Hemophagocytic lymphohistiocytosis (HLH) is frequently lethal in its early phase due to complicating disseminated intravascular coagulation (DIC). The authors report a 14-mo-old girl with severe DIC complicating Epstein-Barr virus associated HLH. She was successfully treated with immunochemotherapy consisting mainly of etoposide and additional recombinant thrombomodulin (r-TM), a newly developed anticoagulant. Although the efficacy of r-TM cannot be proven in a single case report, additional anticoagulation therapy with r-TM is safe and may reduce early deaths in patients with DIC-complicated severe HLH. More clinical experience is required, although r-TM is currently licensed only in Japan.

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  • Primary orbital neuroblastoma in a 1-month-old boy. International journal

    Natsuko Inazawa, Naoki Hatakeyama, Tsukasa Hori, Masaki Yamamoto, Keita Igarashi, Hasegawa Tadashi, Jiro Ogino, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    Pediatrics international : official journal of the Japan Pediatric Society   56 ( 1 )   122 - 5   2014.2

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    Neuroblastoma is a malignant tumor predominantly occurring in children and usually arising from the adrenal gland or sympathetic ganglia. We describe a neuroblastoma in a 1-month-old boy arising from his left orbital cavity. This tumor was refractory to chemotherapy or radiotherapy, requiring enucleation of the left eye for complete removal of the intraorbital tumor. Thereafter, he received high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation, and has been in complete remission for 3 years. Unlike neuroblastomas arising from the adrenal gland or sympathetic ganglia, primary orbital neuroblastoma may be refractory even in early infancy.

    DOI: 10.1111/ped.12239

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  • Multiple intracranial tumors in Philadelphia chromosome-positive acute lymphoblastic leukemia.

    Naoki Hatakeyama, Tsukasa Hori, Masaki Yamamoto, Natsuko Inazawa, Keita Igarashi, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    International journal of hematology   97 ( 4 )   441 - 2   2013.4

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  • Successful treatment of childhood hypocellular acute myeloid leukemia. International journal

    Masaki Yamamoto, Tsukasa Hori, Naoki Hatakeyama, Keita Igarashi, Kotoe Iesato, Katsuya Nakanishi, Hiroko Noguchi, Hayato Miyachi, Masafumi Ito, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    Journal of pediatric hematology/oncology   34 ( 5 )   398 - 401   2012.7

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    Hypocellular acute myeloid leukemia (AML) is extremely rare in childhood. We report on a 7-year-old girl with hypocellular AML who was treated successfully with granulocyte-colony stimulating factor (G-CSF) and combined chemotherapy. High-dose G-CSF induced complete remission and she subsequently received reduced intensity conditioning and unrelated cord blood transplantation; however, this resulted in early rejection. After a complete hematological recovery, she received 3 courses of combination chemotherapy oriented toward AML. She has remained in complete remission for over 1 year after the completion of the therapy. G-CSF effectively induced remission, and combination chemotherapy has been proven to be feasible for patients with childhood hypocellular AML.

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  • [A case of acute lymphotic leukemia which was difficult to make a diagnosis of CRMO for moving arthralgia and periarticular swelling].

    Toshitaka Kizawa, Shinnsuke Katou, Hiroko Shigetomi, Tohjyu Tanaka, Kazuki Iida, Kazushige Nagai, Keita Igarashi, Masaki Yamamoto, Naoki Hatakeyama, Nobuhiro Suzuki, Hiroyuki Tsutsumi

    Nihon Rinsho Men'eki Gakkai kaishi = Japanese journal of clinical immunology   35 ( 2 )   150 - 5   2012

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    A girl, 7 years of age, was reported who had been suffered from migratory arthralgia, bone pain and erythematous rash. She had increased inflammatory markers such as C-reactive protein, erythrocyte sedimentation rate, and mild anemia for more than 6 months. In the beginning, she was suspected of having either juvenile idiopathic arthritis or chronic recurrent multifocal osteomyelitis. However, after about 6 months, there were abrupt increases of LDH in serum titers and blast cells were also revealed by bone marrow examination. Upon these findings, she was diagnosed with acute lymphocytic leukemia. Since bone pain and arthralgia bone pain and arthralgia are both indicative of numerous inflammatory disorders such as infectious myelitis, juvenile chronic arthritis, childhood leukemia and malignancies, and auto-inflammatory bone diseases, especially chronic recurrent multifocal osteomyelitis, it is difficult to accurately diagnose right away. For now, these aforementioned inflammatory responses are the sole key findings for clinical investigations. Other than that, there are not enough reports yet to help diagnose incases similar to this. Therefore, it is difficult to differentiate between the disorders above even after blood tests, Ga-scincigraphy, and imaging examinations. Moreover, in the case of childhood leukemia, it was difficult to differentiate these diseases by routine X-ray surveys in the general pediatric fields. The reasons are because there are only a few descriptions on X-ray bone examinations on findings of X-ray bone investigations, and both are usually non-specific. However, according to the pediatric radiology specialists, of which there are only a few in Japan, the imaging results show somewhat abnormal findings could be spotted from the early stage. Through this present case, it is suggested to us that it is important to consult the pediatric radiology specialists in order to speed up the diagnostic process. Furthermore, the accumulation of radiological findings of leukemia in children with bone pain and arthralgia will attribute to an early diagnosis and lead to the resolution of pathogenesis of leukemia.

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  • Platelet transfusion refractoriness attributable to HLA antibodies produced by donor-derived cells after allogeneic bone marrow transplantation from one HLA-antigen-mismatched mother. International journal

    Naoki Hatakeyama, Tsukasa Hori, Masaki Yamamoto, Natsuko Inazawa, Kotoe Iesato, Toru Miyazaki, Hisami Ikeda, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    Pediatric transplantation   15 ( 8 )   E177-82   2011.12

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    PTR is a serious problem in patients being treated for hematologic disorders. Two patients with acute leukemia developed PTR after allogeneic BMT from one HLA-antigen-mismatched mother attributable to HLA antibodies, which could not be detected in their serum before BMT. HLA antibodies, whose specificity resembled that of each patient, were detected in each donor's serum. Each donor had probably been immunized during pregnancy by their partner's HLA antigens expressed by the fetus, consequently, transplanted donor-derived cells provoked HLA antibodies in each recipient early after BMT, and those HLA antibodies induced PTR. If the mothers are selected as donors for their children, they should be tested for the presence of HLA antibodies.

    DOI: 10.1111/j.1399-3046.2010.01365.x

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  • Infantile acute promyelocytic leukemia without an RARα rearrangement. International journal

    Tsukasa Hori, Nobuhiro Suzuki, Naoki Hatakeyama, Masaki Yamamoto, Natsuko Inazawa, Hayato Miyachi, Tomohiko Taki, Hiroyuki Tsutsumi

    Pediatrics international : official journal of the Japan Pediatric Society   53 ( 6 )   1070 - 3   2011.12

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  • Early expression of plasma CCL8 closely correlates with survival rate of acute graft-vs.-host disease in mice. International journal

    Masaki Yamamoto, Akinobu Ota, Tsukasa Hori, Shin-Ichi Imai, Hitoshi Sohma, Nobuhiro Suzuki, Naoki Hatakeyama, Natsuko Inazawa, Yoichi M Ito, Hiromitsu Kimura, Hiroyuki Tsutsumi, Yasuo Kokai

    Experimental hematology   39 ( 11 )   1101 - 12   2011.11

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    OBJECTIVE: To elucidate the significance of early expression of CC-chemokine ligand motif 8 (CCL8) in mice with graft-vs.-host disease (GVHD), we investigated its induction mechanisms and correlation with overall survival rate in GVHD mice. Plasma CCL8 increases on day 5 of allogeneic transplantation, when signs of GVHD are barely detectable. Increase of allogeneic splenocytes in grafts exacerbates GVHD and leads to upregulation of plasma CCL8 on day 5. Overall survival is the gold standard in determining the severity of acute GVHD in mice, but the absence of clinical and/or pathological manifestations in the early phase make it difficult to estimate vital outcomes at this stage of allogeneic marrow transplantation. MATERIALS AND METHODS: After lethal irradiation, BALB/c mice received bone marrow transplantation from C57BL/6 mice. Survival rate was monitored and clinical and pathological scores of GVHD were examined. Coculture of BALB/c-derived dendritic cells and C57BL/6-derived splenocytes was performed. CCL8 was measured by immunoassay. RESULTS: The plasma CCL8 level at day 5 of transplantation was closely correlated with survival rate and clinical/pathological scores on day 14. In vitro study revealed that the BALB/c-derived dendritic cells expressed CCL8 upon stimulation of C57BL/6 CD4(+) T cells by cell interactions through major histocompatibility complex class II molecules. CONCLUSIONS: These investigations indicate that early and preclinical expression of CCL8 in plasma predicts overall survival of GVHD mice. Together with an involvement of allo-recognition in CCL8 expression, it suggests that CCL8 plays an important role in GVHD pathology.

    DOI: 10.1016/j.exphem.2011.07.006

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  • An evaluation of peripherally inserted central venous catheters for children with cancer requiring long-term venous access.

    Naoki Hatakeyama, Tsukasa Hori, Masaki Yamamoto, Nobuo Mizue, Natsuko Inazawa, Keita Igarashi, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    International journal of hematology   94 ( 4 )   372 - 377   2011.10

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    Long-term venous access is essential when treating malignant diseases. We reviewed our experience with peripherally inserted central venous catheters (PICC) in children suffering from various malignancies with regard to catheter life, reasons for removal, and complications. Ninety-three PICCs were inserted in 78 children. Median catheter life was 162 days (range 6-575 days) with a total of 16,266 catheter days. Seventy-five PICCs (80.6%) had been placed until the elective removal or patients' death, whereas 18 PICCs (19.4%) were removed due to PICC-related complications; a rate of 1.11 per 1,000 catheter days. Complications requiring removal of PICCs included infection (n = 12), occlusion (n = 3), dislodgement (n = 2), and phlebitis (n = 1) with rates of 0.74, 0.18, 0.12 and 0.06 per 1,000 catheter days, respectively. We conclude that PICC provides reliable long-term intravenous access in children suffering from malignancies.

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  • Human cytomegalovirus UL97 D605E polymorphism has a high prevalence in immunocompetent Japanese infants and children. International journal

    Kaori Tanaka, Tsukasa Hori, Yuko Yoto, Naoki Hatakeyama, Masaki Yamamoto, Nobuhiro Suzuki, Hiroyuki Tsutsumi

    Microbiology and immunology   55 ( 5 )   328 - 30   2011.5

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    There is no existing data on UL97 mutation in human cytomegalovirus (HCMV) isolates obtained from individuals who have never been exposed to ganciclovir (GCV). UL97 codons 439 to 645 from 61 CMV isolates from 61 immunocompetent Japanese infants and children were sequenced directly. No known GCV resistance mutations were found, meaning that the UL97 mutation had resulted from the use of GCV. On the other hand, a mutation at codon 605 (D to E) was frequently identified (56/61: 91.8%). This could be a genetic marker for HCMV in East Asian counties, because of its low prevalence in the strains of HCMV circulating in Western countries.

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  • Successful treatment of refractory Langerhans cell histiocytosis with pulmonary aspergillosis by reduced-intensity conditioning cord blood transplantation. International journal

    Naoki Hatakeyama, Tsukasa Hori, Masaki Yamamoto, Natsuko Inazawa, Yoko Hirako, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    Pediatric transplantation   14 ( 3 )   E4-10   2010.5

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    The prognosis of multisystem LCH in children with risk organ involvement is extremely poor when they fail to respond to conventional chemotherapy. In such patients, allogeneic SCT may produce complete and sustained remission; however, high-dose myeloablative regimens are frequently associated with treatment-related morbidity and mortality. More recently, allogeneic SCT following an RIC regimen has been performed as an alternative salvage approach. We describe a nine-month-old boy with refractory multisystem LCH with pulmonary aspergillosis who was successfully treated with reduced-intensity cord blood transplantation.

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  • An infant with self-healing cutaneous Langerhans cell histiocytosis followed by isolated thymic relapse. International journal

    Naoki Hatakeyama, Tsukasa Hori, Masaki Yamamoto, Ineko Sogawa, Natsuko Inazawa, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    Pediatric blood & cancer   53 ( 2 )   229 - 31   2009.8

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    Thymic involvement with Langerhans cell histiocytosis (LCH) typically occurs in children as part of multi-system (M-S) LCH. Patients who develop skin-only LCH during infancy may either follow a self-healing course with spontaneous regression or may progress to M-S involvement. We describe a male infant who developed isolated thymic LCH after spontaneous complete regression of isolated cutaneous lesions. His erythrocyte sedimentation rate and C-reactive protein increased temporarily during the skin-only stage of LCH, and increased again considerably during the thymic relapse. Even for patients with skin-only LCH, these laboratory data might indicate possible relapse or late progression of the disease.

    DOI: 10.1002/pbc.22026

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  • Treatment of an infant with severe acute refractory immune thrombocytopenic purpura using combination therapy including rituximab. International journal

    Kotoe Iesato, Naoki Hatakeyama, Masaki Yamamoto, Tsukasa Hori, Natsuko Inazawa, Hiroyuki Tsutsumi, Nobuhiro Suzuki

    Pediatric blood & cancer   53 ( 2 )   203 - 5   2009.8

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    Some infants with acute immune thrombocytopenic purpura (ITP) do not respond to first-line therapy, and currently there is no consensus on therapy for these refractory cases. We describe a 12-week-old infant with acute ITP who was unresponsive to intravenous immunoglobulin and corticosteroid, and developed gastrointestinal bleeding. Several combination therapies were unsuccessful. After four doses of rituximab followed by intravenous immunoglobulin and corticosteroid, his platelet counts gradually increased. Combined therapy which includes rituximab may be a promising treatment for severe acute refractory ITP.

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  • Occurrence of the African subgroup (Ia) of BK polyomavirus in younger Japanese children Reviewed

    Kaori Tanaka, Tsukasa Hori, Naoki Hatakeyama, Masaki Yamamoto, Rumiko Takayama, Yuko Yoto, Nobuhiro Suzuki, Toshiaki Hayashi, Yukiho Ikeda, Hiroshi Ikeda, Tadao Ishida, Hiroyuki Tsutsumi

    MICROBIOLOGY AND IMMUNOLOGY   53 ( 6 )   319 - 322   2009.6

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  • Upregulation of plasma CCL8 in mouse model of graft-vs-host disease. International journal

    Akinobu Ota, Masaki Yamamoto, Tsukasa Hori, Shunsuke Miyai, Yasuyoshi Naishiro, Hitoshi Sohma, Masahiro Maeda, Yasuo Kokai

    Experimental hematology   37 ( 4 )   525 - 31   2009.4

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    OBJECTIVE: Using a proteomic approach, we recently identified plasma CCL8 as a potential biomarker for diagnosis of graft-vs-host-disease (GVHD) in mice as well as humans. Because mass spectrometric analysis is only semi-quantitative, a quantitative method of measuring plasma CCL8 levels in mice is needed. MATERIALS AND METHODS: We established an enzyme-linked immunosorbent assay for the quantitative measurement of CCL8 concentrations in mouse plasma. RESULTS: Our newly established enzyme-linked immunosorbent assay revealed that the plasma CCL8 concentrations (mean +/- standard error; n=12) were 1287+/-55.7 ng/mL and 1604+/-110.8 ng/mL on days 7 and 14 after allogeneic bone marrow transplantation (BMT), respectively, while the plasma concentrations was 316.6+/-16.3 ng/mL on day 7 after syngeneic BMT. A Western blotting analysis also showed a difference in the plasma CCL8 levels between the allogeneic and syngeneic BMT groups, as did clinical GVHD scores. Neither lipopolysaccharide nor poly(I:C) elevated the plasma CCL8 concentrations, although a dramatic increase in interleukin-6 was detected after both treatments. CONCLUSION: An elevated plasma CCL8 concentration may be a promising plasma marker for GVHD in mouse models.

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  • Quantification of BK polyoma viruria in Japanese children and adults with hemorrhagic cystitis complicating stem cell transplantation. International journal

    Kaori Tanaka, Tsukasa Hori, Naoki Hatakeyama, Masaki Yamamoto, Rumiko Takayama, Yuko Yoto, Nobuhiro Suzuki, Toshiaki Hayashi, Yukiho Ikeda, Hiroshi Ikeda, Tadao Ishida, Hiroyuki Tsutsumi

    Journal of medical virology   80 ( 12 )   2108 - 12   2008.12

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    Polyoma BK virus (BKV) is frequently found in the urine of stem cell transplantation (SCT) patients with hemorrhagic cystitis (HC), but also occurs in SCT patients without HC. How BK viruria relates to the development of HC in SCT patients, especially in children, has not yet been fully evaluated. In the present study, we analyzed the relationship of several factors including urinary BKV load to HC development in children and adults undergoing SCT. We employed a quantitative PCR assay and evaluated 37 patients (aged 9 months-62 years) of whom 12 developed HC and 25 did not. Older age was a risk factor for the development of HC; however, other factors such as sex, primary disease, type of SCT, conditioning regimen and aGVHD were not. Peak urinary BKV values in HC patients were not higher than those in non-HC patients. Severity of HC also did not correlate with urinary BKV loads. However, in some patients who secreted higher urinary BKV loads, the peak loads were closely related with the onset of HC. Higher BKV loads may be a risk factor for the development of HC in conjunction with other coexisting factors.

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  • CCL8 is a potential molecular candidate for the diagnosis of graft-versus-host disease. International journal

    Tsukasa Hori, Yasuyoshi Naishiro, Hitoshi Sohma, Nobuhiro Suzuki, Naoki Hatakeyama, Masaki Yamamoto, Tomoko Sonoda, Yuka Mizue, Kohzoh Imai, Hiroyuki Tsutsumi, Yasuo Kokai

    Blood   111 ( 8 )   4403 - 12   2008.4

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    Although graft-versus-host disease (GVHD) is a life-threatening complication of hematopoietic stem-cell transplantation (HSCT), its current diagnosis depends mainly on clinical manifestations and invasive biopsies. Specific biomarkers for GVHD would facilitate early and accurate recognition of this grave condition. Using proteomics, we screened for plasma proteins specific for GVHD in a mouse model. One peak with 8972-Da molecular mass (m/z) retained a discriminatory value in 2 diagnostic groups (GVHD and normal controls) with increased expression in the disease and decreased expression during cyclosporin A treatment, and was barely detectable in syngeneic transplantation. Purification and mass analysis identified this molecule as CCL8, a member of a large chemokine family. In human samples, the serum concentration of CCL8 correlated closely with GVHD severity. All non-GVHD samples contained less than 48 pg/mL (mean +/- SE: 22.5 +/- 5.5 pg/mL, range: 12.6-48.0 pg/mL, n = 7). In sharp contrast, CCL8 was highly up-regulated in GVHD sera ranging from 52.0 to 333.6 pg/mL (mean +/- SE: 165.0 +/- 39.8 pg/mL, n = 7). Strikingly, 2 patients with severe fatal GVHD had extremely high levels of CCL8 (333.6 and 290.4 pg/mL. CCL8 is a promising specific serum marker for the early and accurate diagnosis of GVHD.

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  • Carbamazepine-induced hemolytic and aplastic crises associated with reduced glutathione peroxidase activity of erythrocytes.

    Masaki Yamamoto, Nobuhiro Suzuki, Naoki Hatakeyama, Noriaki Kubo, Nobutada Tachi, Hitoshi Kanno, Hisaichi Fujii, Hiroyuki Tsutsumi

    International journal of hematology   86 ( 4 )   325 - 8   2007.11

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    Although pure red cell aplasia is a well-known side effect of carbamazepine treatment, intravascular hemolytic anemia is rare. We describe a 5-year-old boy who developed concurrent intravascular hemolytic anemia and erythroblastopenia, probably due to carbamazepine. Carbamazepine treatment was subsequently discontinued, and the patient was treated with red blood cell transfusions, haptoglobin, and methylprednisolone. His hematologic abnormalities were almost fully recovered within 2 weeks. Examination of the patient's and mother's erythrocyte enzyme activities revealed mildly decreased erythrocyte glutathione peroxidase (GSH-Px) activity. We speculate that patients with reduced GSH-Px activity are at a high risk of developing carbamazepine-induced hemolytic crisis and/or aplastic crisis.

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  • Quantification of adenovirus species B and C viremia by real-time PCR in adults and children undergoing stem cell transplantation. International journal

    Rumiko Takayama, Naoki Hatakeyama, Nobuhiro Suzuki, Masaki Yamamoto, Toshiaki Hayashi, Yukiho Ikeda, Hiroshi Ikeda, Hideki Nagano, Tadao Ishida, Hiroyuki Tsutsumi

    Journal of medical virology   79 ( 3 )   278 - 84   2007.3

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    Adenovirus infection during stem cell transplantation is associated with high morbidity and mortality. Adenovirus species B and C have been the main causes for these infections; however, epidemiological details about the species are still unclear. To clarify the contributions of species B and C adenovirus, the DNA was tested serially by quantitative real-time PCR in peripheral blood, stool and urine of 32 patients (16 adults and 16 children) undergoing stem cell transplantation. Adenovirus species B viremia was detected in 10 of 16 adult and 6 of 16 pediatric transplant recipients. Adenovirus species C viremia was also detected simultaneously in five adult and three pediatric recipients. The stool and urine of patients with adenovirus viremia were also positive for the same adenovirus species as in blood. In contrast, in none of 50 healthy adult controls was adenovirus species B or C viremia detected. Among patients who developed adenovirus viremia, one adult recipient developed disseminated disease and died from multiple organ failure. The remaining patients experienced fever of several degrees and/or diarrhea during the period of adenovirus viremia; however, they all recovered without antiviral therapy. The results indicated that stem cell transplantation was frequently associated with adenovirus species B or C viremia, although it did not always cause serious infectious complications.

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  • Treatment of McLeod phenotype chronic granulomatous disease with reduced-intensity conditioning and unrelated-donor umbilical cord blood transplantation.

    Nobuhiro Suzuki, Naoki Hatakeyama, Masaki Yamamoto, Nobuo Mizue, Yuki Kuroiwa, Minami Yoda, Junko Takahashi, Yoshihiko Tani, Hiroyuki Tsutsumi

    International journal of hematology   85 ( 1 )   70 - 2   2007.1

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    Patients with chronic granulomatous disease (CGD) complicated by antimycotics-refractory invasive aspergillosis have an extremely poor prognosis if they cannot undergo allogeneic hematopoietic stem cell transplantation from a suitable related donor while in good clinical condition. We successfully treated a 20-year-old man with very rare McLeod phenotype CGD with reduced-intensity conditioning and unrelated-donor umbilical cord blood transplantation. We postulate that reduced-intensity conditioning-allogeneic hematopoietic stem cell transplantation is a promising therapeutic strategy for patients with CGD even if only unrelated-donor umbilical cord blood is available.

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  • Treatment of stage IV malignant rhabdoid tumor of the kidney (MRTK) with ICE and VDCy: a case report. International journal

    Masaki Yamamoto, Nobuhiro Suzuki, Naoki Hatakeyama, Nobuo Mizue, Tsukasa Hori, Yuki Kuroiwa, Masato Hareyama, Takanori Oda, Tooru Kudoh, Akihiro Nui, Takashi Matsuno, Toshinori Hirama, Shigeaki Yokoyama, Jeffrey S Dome, Hiroyuki Tsutsumi

    Journal of pediatric hematology/oncology   28 ( 5 )   286 - 9   2006.5

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    The prognosis of stage IV malignant rhabdoid tumor of the kidney (MRTK) has been extremely poor. However, a combination of ICE (ifosfamide, carboplatin, and etoposide) and VDCy (vincristine, doxorubicin, and cyclophosphamide) was recently reported to be effective for metastatic MRTK. We describe a 21-month-old girl with stage IV MRTK who was successfully treated with ICE, VDCy, and radiotherapy. She remained well, without recurrence, 24 months after diagnosis. Alternating therapy with ICE and VDCy might become a standard regimen for stage IV MRTK, although further study is required to confirm its effectiveness.

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  • Detection of BK virus and adenovirus in the urine from children after allogeneic stem cell transplantation. International journal

    Naoki Hatakeyama, Nobuhiro Suzuki, Masaki Yamamoto, Yuki Kuroiwa, Tsukasa Hori, Nobuo Mizue, Hiroyuki Tsutsumi

    The Pediatric infectious disease journal   25 ( 1 )   84 - 5   2006.1

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    The development of hemorrhagic cystitis (HC) and urinary excretion of polyoma BK virus (BKV) and adenovirus (ADV) was investigated by polymerase chain reaction in 20 children undergoing allogeneic stem cell transplantation. Five children developed HC, and all of them excreted BKV; however, only 1 excreted ADV, suggesting that BKV is more significant cause of HC than ADV in children undergoing stem cell transplantation.

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  • Crohn's disease in a child with Down syndrome. International journal

    Masaki Yamamoto, Wataru Abo, Tsukasa Hori, Toshimasa Nakada, Naoki Tachibana, Yasumasa Hatada, Mitsuomi Kaimori

    Pediatrics international : official journal of the Japan Pediatric Society   44 ( 5 )   537 - 9   2002.10

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    Language:English   Publishing type:Research paper (scientific journal)  

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Research Projects

  • 学童期から思春期の子どもの小児がん医療における意思形成過程の解明と支援方法の開発

    Grant number:21K02409  2021.4 - 2024.3

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    道信 良子, 山本 雅樹, 五十嵐 敬太

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    Grant amount:\4030000 ( Direct Cost: \3100000 、 Indirect Cost:\930000 )

    学童期に小児がんを発症した子どもたちが、自分に対する医療や自分の身体に対してどのような過程を経て、自分の小児がん医療に対する意思を形成していくのかを明らかにするために、臨床における短い参与観察とインフォーマル・インタビューを行った。5歳から12歳までに小児がんを発症し、半年以上の入院生活を経験している子ども12人を対象とした。新型コロナウイルス感染症の予防のため、子どもと面会する時間は15分以内とし、面会が禁止されている期間はカルテからの情報を得た。面会が解除されたら、医師の回診にも付き添い、子どもと医療者とのかかわりを観察した。以上の継続的な焦点化した調査をふまえて、小児がん医療に学際的な子ども学の視点を取り入れ、小児がん医療における子どもの意思決定を支援していくための理論的枠組を検討した。それは、子どもの成長と医師の育みを視野にいれながら、子どもと周囲の人との「関係性」に着目した意思決定である。この結果は、国際小児がん学会に抄録としてまとめ、提出した。現在査読中である。方法論の検討は十分に進んでいないが、新型コロナウイルス感染症対策もふまえ、斬新な方法が必要であり、研究に参加している家族の意向をたずねている。なお、地域の参与観察( 子どもと家族が住んでいる地域での催しや行事に許可を得て参加すること)も、感染症対策の観点から遠隔での調査を現在検討している。学校における健康づくりや身体のケアに関する子どもの意思決定とその支援の現状についても、次年度に検討したい。

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  • CCL8制御で介入した移植片対宿主病における病態解析の基礎的研究

    Grant number:21K07823  2021.4 - 2024.3

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    五十嵐 敬太, 山本 雅樹, 赤根 祐介, 浜田 亮

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    Grant amount:\4030000 ( Direct Cost: \3100000 、 Indirect Cost:\930000 )

    ドナーとしてC57BL/6(B6)マウス(H-2b, I-Ab)、レシピエントとしてBALB/cマウス(H-2d, I-Ad)を使用し、レシピエントマウスにドナーマウスの骨髄細胞と脾臓細胞を移植することで致死的急性移植片対宿主病(GVHD)を誘導した。
    ドナーがB6-野生型(WT)でレシピエントがBALB/c-WTマウスの移植群と、ドナーがB6-CCL8ノックアウト(CCL8KO)マウスでレシピエントが同じくBALB/c-WTの移植群のアウトカムを比較した。移植後の体重減少に有意差はなく、移植後day1とday4のELISA測定による末梢血のCCL8発現も同等であった。両移植群ともに移植後day7までには全例早期死亡し、log-rank検定では生存率に差を認めなかった。
    結果から、ドナーのCCL8欠損は重症GVHDを誘導する移植モデルでは生存率に影響を与えないことが示唆された。

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  • Pathological analysis of acute graft-versus-host disease and development of molecular targeted therapy for acute GVHD

    Grant number:15K09657  2015.4 - 2018.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    Yamamoto Masaki

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    Grant amount:\4940000 ( Direct Cost: \3800000 、 Indirect Cost:\1140000 )

    We performed mixed leukocyte reaction assay using wild type and CCL8-knockout mice. CCL8 protein were not detected in the supernatant of CCL8 KO mice. Also we preformed RNA interference assay with ccl8 specific siRNA. By the RNAi, CCL8 protein were slightly decreased in the supernatant. Thus, gene manipulation maybe the treatment option of acute GVHD
    To explore the role of Chemokine (C-C motif) ligand 8 (CCL8) as a potential biomarker for acute graft-versus-host disease (aGVHD), we retrospectively analyzed the sera and clinical course of 31 patients with grade II to IV aGVHD. No deaths occurred in the ten patients with serum CCL8 concentrations less than 213 pg/mL, whereas 11 of the 21 patients with more than 213 pg/mL died within 180 days post-transplantation. Thus, elevated serum CCL8 concentration before day 100 post-transplantation may predict aGVHD prognosis.

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  • Analysis of molecular function of CCL8 as a biomarker for acute graft-versus-host disease

    Grant number:22790990  2010 - 2011

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    YAMAMOTO Masaki

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    Grant amount:\3900000 ( Direct Cost: \3000000 、 Indirect Cost:\900000 )

    We studied about chemokine CCL8 as a biomarker of acute graft-versus-host disease(GVHD). The plasma CCL8 concentration in GVHD mouse model showed correlated with the severity and the prognosis of GVHD mice. Similarly, serum CCL8 concentration may reflect the response to the treatment against GVHD and correlate with the severity of GVHD in human.

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  • Development of the quantitative method and the analysis of function of the molecular marker for acute graft-versus-host disease.

    Grant number:20790735  2008 - 2009

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    YAMAMOTO Masaki

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    Grant amount:\4290000 ( Direct Cost: \3300000 、 Indirect Cost:\990000 )

    We studied about chemokine CCL8 as a biomarker of acute graft-versus-host disease (GVHD). We developed ELISA for plasma CCL8 level in the GVHD mouse models. We analyzed the expression mechanism of CCL8 using in vitro and in vivo model.

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  • Impact of Mesenchymal stem cell transplantation in mouse GVHD model

    Grant number:18591195  2006 - 2007

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    SUZUKI Nobuhiro, HATAKEYAMA Naoki, YAMAMOTO Masaki, HORI Tsukasa

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    Grant amount:\3880000 ( Direct Cost: \3400000 、 Indirect Cost:\480000 )

    Using mouse model for graft versus host disease (GVHD), we studied effects of mesenchymal stem cell (MSC) on severity, prognosis of GVHD. 2×107 bone marrow cells isolated form C57BL/6 mice were transplanted to lethally irradiated BALB/c mice. An apparent GVHD was observed 7 days after marrow transplantation (BMT), which continued to day 28, the last day for observations. To develop various severity in GVHD, we added various number of spleen cells obtained from C57BL/6 mice. 1×10 spleen cells plus 1×107 marrow cells developed lethal GVHD. More than 50% of recipients dyed before day14. Using this very severe GVHD model, we exploited whether transplantation of MSC decrease GVHD severity in this particular model. MSC were prepared using Mruine Mesencult culture system. Cell surface markers of our MSC were CD45^-, CD11b-, Sca+, CD44+. These MSC could differentiate to osteoblasts and lipocytes under appropriate conditions. Using various number of MSC, GVHD model was challenged for effects of MSC transplantation. MSCs were transplanted on either the day of BMT or one day after BMT. These mice were compared to those of non MSC recipient mice which were received only bone marrow cells. Clinical symptom, body weight, survival date and pathological findings were studied at day7, 14,21 and 28 after BMT, though none of these findings were changed in both MSC recipients and BMT only recipients. We are planning to do BMT with immunosuppressive reagent plus MSC on different severity of GVHD model as a next trial

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