Details of a Researcher - YAMAMOTO Masaki

Papers - YAMAMOTO Masaki

Division display 21 - 40 of about 46 ／ All the affair displays >>

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

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 2015.04 [International journal]

DOI PubMed

Multiplex PCR for Virus Infections after Allogeneic Hematopoietic Stem Cell Transplantation

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

BLOOD ( AMER SOC HEMATOLOGY ) 124 ( 21 ) 2014.12 [Refereed]

Cord blood transplantation is associated with rapid B-cell neogenesis compared with BM transplantation

K. Nakatani, K. Imai, M. Shigeno, H. Sato, M. Tezuka, T. Okawa, N. Mitsuiki, T. Isoda, D. Tomizawa, M. Takagi, M. Nagasawa, M. Kajiwara, M. Yamamoto, A. Arai, O. Miura, C. Kamae, N. Nakagawa, K. Honma, S. Nonoyama, S. Mizutani, T. Morio

BONE MARROW TRANSPLANTATION ( NATURE PUBLISHING GROUP ) 49 ( 9 ) 1155 - 1161 2014.09 [Refereed]

Hematopoietic cell transplantation (HCT) is used for treatment of hematopoietic diseases. Assessment of T-and B-cell reconstitution after HCT is crucial because poor immune recovery has a major effect on the clinical course. In this study, we retrospectively analyzed T-cell receptor excision circles (TRECs) as well as signal and coding joint kappa-deleting recombination excision circles (sjKRECs and cjKRECs, respectively) as markers of newly produced lymphocytes in 133 patients (56 primary immunodeficient and 77 malignant cases, median (range): 12 (0-62) years old). We analyzed the kinetics of TREC and KREC recovery and determined the factors that contributed to better immune recovery. KRECs became positive earlier than TRECs and increased thereafter. Younger recipient age had a favorable effect on recovery of sjKRECs and cjKRECs. Compared with BM and peripheral blood, our data suggested that cord blood (CB) provided rapid B-cell recovery. CB also provided better B-cell neogenesis in adult HCT recipients. Chronic GVHD was associated with low TRECs, but not increased sjKRECs/cjKRECs. Finally, positive sjKRECs 1 month after HCT were associated with fewer infectious episodes. Monitoring of TRECs and KRECs may serve as a useful tool for assessment of immune reconstitution post HCT.

DOI

Cushing's disease developing independently from acute lymphoblastic leukemia.

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 2014.09 [International journal]

PubMed

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

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

Indian journal of pediatrics 81 ( 3 ) 288 - 91 2014.03 [International journal]

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.

DOI PubMed

Primary orbital neuroblastoma in a 1-month-old boy.

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 2014.02 [International journal]

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 PubMed

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 2013.04 [Domestic journal]

DOI PubMed

Successful treatment of childhood hypocellular acute myeloid leukemia.

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 2012.07 [International journal]

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.

DOI PubMed

[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 [Domestic journal]

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.

PubMed

Infantile acute promyelocytic leukemia without an RARα rearrangement.

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 [International journal]

DOI PubMed

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

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 [International journal]

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 PubMed

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

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 [International journal]

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 PubMed

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 [Domestic journal]

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.

DOI PubMed

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

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

Microbiology and immunology 55 ( 5 ) 328 - 30 2011.05 [International journal]

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.

DOI PubMed

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

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

Pediatric transplantation 14 ( 3 ) E4-10 2010.05 [International journal]

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.

DOI PubMed

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

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

Pediatric blood & cancer 53 ( 2 ) 203 - 5 2009.08 [International journal]

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.

DOI PubMed

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

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

Pediatric blood & cancer 53 ( 2 ) 229 - 31 2009.08 [International journal]

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 PubMed

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

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

Experimental hematology 37 ( 4 ) 525 - 31 2009.04 [International journal]

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.

DOI PubMed

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

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 [International journal]

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.

DOI PubMed

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

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 2008.04 [International journal]

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.

DOI PubMed

　 PREV - NEXT 　

<YAMAMOTO Masaki>

Papers - YAMAMOTO Masaki