Details of a Researcher - YAMAMOTO Masaki

Papers - YAMAMOTO Masaki

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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 & Cancer ( Wiley ) 2024.06

DOI

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

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

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

DOI PubMed

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 2021.03 [Domestic journal]

DOI PubMed

Familial Mediterranean Fever After Cord Blood Transplantation for Familial Hemophagocytic Lymphohistiocytosis.

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 2021.02 [International journal]

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 PubMed

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

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

Pediatrics international : official journal of the Japan Pediatric Society 63 ( 2 ) 221 - 223 2021.02 [International journal]

DOI PubMed

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

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 2021.01 [International journal]

DOI PubMed

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

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 [International journal]

DOI PubMed

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

Bone marrow transplantation 56 ( 5 ) 1013 - 1020 2020.09 [International journal]

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 PubMed

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

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

Pediatrics international : official journal of the Japan Pediatric Society 62 ( 3 ) 403 - 405 2020.03 [International journal]

DOI PubMed

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

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 ( 日本臨床外科学会 ) 80 ( 12 ) 2303 - 2303 2019.12 [Refereed]

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

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 [International journal]

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 PubMed

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

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 2018.07 [International journal]

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 PubMed

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

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 2018.06 [International journal]

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 PubMed

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 2018.04 [Domestic journal]

DOI PubMed

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

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 2018.04 [International journal]

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 PubMed

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

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

Pediatrics international : official journal of the Japan Pediatric Society 60 ( 1 ) 85 - 87 2018.01 [International journal]

DOI PubMed

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 [Domestic journal]

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 PubMed

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

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 2017.02 [International journal]

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 PubMed

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.

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 2016.02 [International journal]

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 PubMed

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

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 2015.08 [International journal]

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.

DOI PubMed

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Papers - YAMAMOTO Masaki