Y Asano

Kyushu University, Hukuoka, Fukuoka, Japan

Are you Y Asano?

Claim your profile

Publications (33)94.31 Total impact

  • Kanzo 01/2007; 48(7):331-337.
  • [Show abstract] [Hide abstract]
    ABSTRACT: We analyzed the structure of the granulocyte colony-stimulating factor (G-CSF) receptor gene in a 6-year-old female patient with severe congenital neutropenia (SCN) who experienced severe recurrent infections since 1 month of age. There is no family history of any similar disease. When the patient was 4 months old, she began receiving treatment with recombinant human G-CSF that resulted in a small increase in the neutrophil count sufficient for the prevention and treatment of bacterial infection. An analysis of complementary DNA for the patient's G-CSF receptor revealed a 3-base pair deletion in the juxtamembrane intracellular sequence. This deletion at the beginning of exon 16 was thought to be caused by alternative splicing; analysis of the DNA revealed a G-to-A point mutation of the final nucleotide of intron 15. To evaluate the functional activity of the G-CSF receptor with this 3-base pair deletion of the juxtamembrane region, we transfected this G-CSF receptor mutant into an interleukin 3-dependent cell line, BAF/3. BAF/3 cells expressing the mutant G-CSF receptor showed augmented proliferation activity in response to G-CSF compared with cells having the wild-type G-CSF receptor. Although the proliferation signal of G-CSF in normal hematopoiesis is transduced through the activation of MAP kinases, this G-CSF receptor mutant showed decreased activation of ERKI/2 in response to G-CSF compared with the wild type, but the transduced sig-nal for Stat3 activation by G-CSF was of the same magnitude as that of the wild-type G-CSF receptor. This result means that the augmented proliferation activity in response to G-CSF that we observed in cells having the G-CSF receptor gene with the 3-base pair deletion is transduced through an intracellular signaling pathway other than MAP kinase. Because SCN patients with a mutation in the G-CSF receptor frequently develop leukemia, this 3-base pair deletion in the juxtamembrane sequence of the G-CSF receptor gene in this patient may be one step in the course of leukemic transformation.
    International Journal of Hematology 08/2005; 82(1):28-34. · 1.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We examined the efficacy of cyclosporin A (CsA) in 50 patients with myelodysplastic syndrome (MDS) consisting from 47 of RA, 1 of RARS, and 2 of RAEB. These patients showed various marrow cell types including hypo-, normo-, and hypercellularity. Patients belonged to the following International Prognostic Scoring System (IPSS) risk groups: 4 of low, 41 of intermediate-1, and 5 of intermediate-2. The median CsA dose was 4.58mg/kg, and treatment responses were classified according to the International Working Group (IWG) criteria. Hematological improvement (HI) was observed in 30 (60%) patients, and all of them were belonged to RA. In the patients with RARS or RAEB, no efficacy was observed. Four (8%) of the responders achieved partial remission (PR) with granulocytes > or = 1500microl(-1), Hb>11g/dl and platelets > or = 100,000microl(-1). Higher response rate (53%) was shown in erythroid lineage (HI-E) compared to platelet (HI-P, 36%) or neutrophil lineage (HI-N, 35%). When we analyzed the correlation between the response to CsA therapy and the karyotype or HLA type, there were significantly more responders with good karyotype or DRB1*1501 than with intermediate/poor karyotypes or with other HLA types. These results indicate the usefulness of CsA therapy for MDS patients with any marrow cellularity, especially for erythroid lineage and patients with good karyotype or DRB1*1501.
    Leukemia Research 09/2003; 27(9):783-8. · 2.76 Impact Factor
  • Journal of Clinical and Experimental Hematopathology 01/2003; 43(2):49-51.
  • Yoshiyuki Niho, Yoshinobu Asano
    Nihon Naika Gakkai Zasshi 08/2002; 91(7):1989-93.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A 17-year-old Japanese woman with Ewing's sarcoma was initially treated with conventional chemotherapy and local irradiation, and then with high-dose chemotherapy supported by autologous peripheral blood stem cell transplantation. Four years later she was diagnosed with chronic myelogenous leukaemia (CML). The BCR/ABL fusion gene was detected in both peripheral blood and bone marrow cells by reverse transcription-polymerase chain reaction, but not in the harvest product of peripheral blood stem cells which were infused at the time of transplantation. This case adds to the accumulating evidence of therapy-related CML developing after high-dose chemotherapy and autologous stem cell transplantation.
    British Journal of Haematology 07/2002; 117(3):613-6. · 4.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Tyk2 is activated in response to interleukin-12 (IL-12) and is essential for IL-12-induced T-cell function, including interferon-gamma (IFN-gamma) production and Th1 cell differentiation. Because IL-12 is a stimulatory factor for natural killer (NK) cell-mediated cytotoxicity, we examined whether tyk2 is required for IL-12-induced NK cell activity. IL-12-induced NK cell activity in cells from tyk2-deficient mice was drastically reduced compared to that in cells from wild-type mice. IL-18 shares its biologic functions with IL-12. However, the molecular mechanism of IL-18 signaling, which activates an IL-1 receptor-associated kinase and nuclear translocation of nuclear factor-kappaB, is different from that of IL-12. We next examined whether biologic functions induced by IL-18 are affected by the absence of tyk2. NK cell activity and IFN-gamma production induced by IL-18 were reduced by the absence of tyk2. Moreover, the synergistic effect of IL-12 and IL-18 for the production of IFN-gamma was also abrogated by the absence of tyk2. This was partially due to the absence of any up-regulation of the IL-18 receptor treated with IL-12, and it might suggest the presence of the cross-talk between Jak-Stat and mitogen-activated protein kinase pathways in cytokine signaling.
    Blood 04/2002; 99(6):2094-9. · 9.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Trials of immunosuppressive therapy have been reported in some case reports of hypoplastic myelodysplastic syndrome (MDS). In this study, we gave immunosuppressive therapies to eight patients with normo- or hyperplastic MDS of refractory anemia subtype without karyotypic abnormalities and analyzed the HLA-DRB1 type or the presence of paroxysmal nocturnal hemoglobinuria (PNH) neutrophils in these patients. Cyclosporin A (CyA) therapy was effective for improving cytopenia in four of the eight MDS patients. While the side effects of CyA were mostly mild and transient, one patient demonstrated karyotypic abnormality following CyA therapy and accelerated to refractory anemia with an excess of blasts. Additional antithymocyte globulin (ATG) therapy was effective in one of three nonresponders to CyA therapy. One patient died due to leukemic transformation after ATG therapy. When we analyzed the correlation between the response to CyA therapy and the HLA-DRB1 type, there were more responders with DRB1*1501 (three of four patients) than without (one of four patients), but a statistically significant difference was not evident between the two groups. In addition, the presence of PNH neutrophils was not correlated with the response to CyA and/or ATG therapy. These results indicate the usefulness of immunosuppressive therapies even for normo- or hyperplastic MDS patients. Further trials using more patients with a long follow-up period would be worthwhile in order to clarify the possibility of disease progression and in order to predict the response of patients.
    Annals of Hematology 12/2001; 80(11):634-8. · 2.87 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A 38-year-old Japanese woman with severe aplastic anemia received an allogeneic bone marrow transplant from her serologically HLA-identical father. Cyclosporine and methotrexate were administered to prevent graft-versus-host disease (GVHD). However, grade III acute GVHD developed on day 44, which was successfully treated with methylprednisolone and tacrolimus. Fluconazole therapy was started for oral candidiasis on day 112, but she complained of headache soon after. In addition to glycosuria and increased serum creatinine levels, Pelger-Huët anomaly of granulocytes was found in her blood, which disappeared after discontinuation of tacrolimus. Transient occurrence of Pelger-Huët cells may be associated with tacrolimus toxicity due to drug interaction with fluconazole.
    Bone Marrow Transplantation 01/2001; 26(11):1255-7. · 3.54 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Janus kinases (Jaks) play an important role in signal transduction via cytokine receptors. Tyk2 is a Janus kinase, and we developed tyk2-deficient mice to study the requirement for tyk2 in vivo. Tyk2-deficient mice show no overt developmental abnormalities; however, they display a lack of responsiveness to a small amount of IFNalpha, although a high concentration of IFNalpha can fully transduce its signal even in the absence of tyk2. Furthermore, IL-12-induced T cell function is defective in these mice. In contrast, these mice respond normally to IL-6 and IL-10, both of which activate tyk2 in vitro. These observations demonstrate that tyk2 plays only a restricted role in mediating IFNalpha-dependent signaling while being required in mediating IL-12-dependent biological responses.
    Immunity 11/2000; 13(4):561-71. · 19.80 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 25-year-old man was diagnosed with acute myelogenous leukemia (AML), French-American-British (FAB) subtype M0, based on cytochemical and flow cytometric findings. Cytogenetic analysis revealed the chromosome translocations t(9;11)(p22;q23), and MLL gene rearrangement was identified by Southern blotting. In adult AML, MLL gene rearrangement was initially reported in FAB M4 and M5 cases, and recently in M1 and M2 cases, but was rare in M0 or M3 cases. Because the sensitivity of detecting MLL gene rearrangement by cytogenetic analysis is extremely low compared with Southern blotting analysis, the MLL gene may be involved in substantial numbers of adult AML cases, regardless of FAB subtype.
    International Journal of Hematology 05/2000; 71(3):245-8. · 1.68 Impact Factor
  • Y Asano, Y Niho
    Nippon rinsho. Japanese journal of clinical medicine 12/1999; 57 Suppl:779-82.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The overproduction of cytokines with inhibitory effects on hematopoiesis is considered to play a role in the pathogenesis of aplastic anemia. While interleukin 10 (IL-10) is a cytokine production inhibitory factor, the possibility of immunosuppressive therapy using IL-10 for aplastic anemia has not been explored. In this study, therefore, we examined the effect of IL-10 on progenitor cells obtained from seven patients with severe aplastic anemia. Our study indicated that IL-10 dramatically enhanced the erythroid colony formation in a dose-dependent manner in two of the seven cases examined. When we examined the concentration of cytokines in the culture supernatants of unstimulated bone marrow cells, the spontaneous production of interferon-gamma (IFN-gamma) was observed in one of these two cases, and this production was completely inhibited by addition of IL-10. These findings suggested that IL-10 enhanced the erythroid colony formation by inhibiting the pathological production of IFN-gamma in this case. This study provides an experimental support for the clinical application of IL-10 in some patients with aplastic anemia.
    Stem Cells 02/1999; 17(3):147-51. · 7.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the present study, we examined the effects of interleukin-3 (IL-3) on the proliferation of leukaemic progenitor cells from 11 Japanese patients with acute myeloblastic leukaemia (AML), including the effect of its combination with granulocyte/macrophage colony-stimulating factor (GM-CSF) or granulocyte colony-stimulating factor (G-CSF). The results showed that IL-3 sufficiently stimulated the proliferation of AML progenitor cells in almost all the cases examined, and that the stimulation pattern of IL-3 was similar to that of GM-CSF, although different from that of G-CSF. Furthermore, IL-3 worked synergistically with G-CSF, whereas IL-3 and GM-CSF together were less actively synergistic (P < 0.05). These findings suggest the possibility of IL-3/G-CSF/cytosine arabinoside (Ara-C) combination therapy, which may be able to enhance the cytotoxic effect of Ara-C on AML progenitor cells powerfully in a wider range of patients including cases refractory for IL-3/Ara-C combination therapy.
    Clinical & Laboratory Haematology 08/1998; 20(4):225-9. · 1.11 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report on a case of adenovirus hemorrhagi cystitis that developed in a 49-year-old woman during intensive chemotherapy for adult T-cell leukemia. Although rapid etiologic diagnosis is essential for the effective management of viral hemorrhagic cystitis, the isolation of adenovirus from urine is often too time-cousuming. We detected the adenovirus antigen in the patient's urine using an Adenoclone direct sandwich ELISA kit (Cambridge Bio Science), which is commonly employed for the diagnosis of adenovirus conjunctivitis. Treatment consisted of intravenous vidarabine and bladder irrigation, which resulted in prompt clinical improvement. The Adenoclone kit was useful for the rapid etiologic diagnosis of adenovirus hemmorrhagic cystitis.
    [Rinshō ketsueki] The Japanese journal of clinical hematology 07/1998; 39(6):460-2.
  • Y Niho, Y Asano
    [Show abstract] [Hide abstract]
    ABSTRACT: Fas antigen is a receptor that crosslinks with a ligand or antibody initiating a signal transduction cascade that leads to apoptosis. During normal hematopoiesis, Fas antigen is not expressed on CD34+ cells, including premature hematopoietic progenitor cells. Functioning Fas antigen expression is induced by several hematopoietic regulators. These changes may appear not only in the process of differentiation of hematopoietic progenitor cells, but also as a negative feedback mechanism that controls chaotic proliferation of these cells. These findings suggest that the Fas/Fas ligand system is closely related to the maintenance of homeostasis during the process of normal hematopoiesis. Furthermore, increased Fas antigen expression is observed on CD34+ cells from patients with aplastic anemia, suggesting that it might cause bone marrow suppression. The use of Fas-mediated apoptosis of malignant cells as a tool for eliminating hematologic malignancies is promising. Increased Fas ligand expression is observed on natural killer lymphoma cells and may be associated with the pathogenesis of failure of several organs. The Fas/Fas ligand system plays an important role in the physiologic and pathologic processes of hematopoiesis. The development of treatments using this system are forthcoming.
    Current Opinion in Hematology 06/1998; 5(3):163-5. · 4.11 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A patient with non-Hodgkin's lymphoma who received a CD34-selected autologous peripheral blood stem cell transplant (PBSCT) developed cytomegalovirus retinitis, adenovirus-associated haemorrhagic cystitis (HC) and fatal herpes simplex virus pneumonia. Depletion of mature T cells from the graft and a persistent decrease in CD4+ lymphocytes following PBSCT may have predisposed this patient to such viral infections. Infusion of cryopreserved autologous PBSC (containing mature T cells) was effective for adenovirus-associated HC. Immunosuppression and resultant viral infections may affect patients receiving CD34-selected autologous transplantation.
    British Journal of Haematology 03/1998; 100(2):348-50. · 4.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The membrane-proximal cytoplasmic region of the granulocyte colony-stimulating factor receptor (G-CSFR) is known to be essential for the proliferation signal, with a more distal region being required for the differentiation signal. Such a separation of functional domains raises the possibility that mutations occurring at these regions may contribute to cell proliferation in the absence of differentiation, this being the most important characteristic in acute leukemia cells. Therefore, we analysed the structural abnormalities at the transmembrane and cytoplasmic region of G-CSFR in a significant number of patients with various myeloid malignancies. When we examined the genomic DNA of G-CSFR obtained from 41 patients with acute myelogenous leukemia (AML), 18 with chronic myelogenous leukemia (CML), 7 with myelodysplastic syndrome (MDS), 2 with chronic myelomonocytic leukemia and 1 with chronic neutrophilic leukemia, we found a polymorphism in 3 patients, but no significant pathogenic mutations in any patients. The screening for this polymorphism in 100 hematologically normal controls revealed that it may be useful as a linkage marker for population and family studies, because the heterozygosity index is at a high level (0.055). While there have been several reports discussing the leukemogenic potential of mutations in the cytokine/hematopoietin receptor superfamily, genetic alterations in the transmembrane and cytoplasmic region of G-CSFR do not seem to play a pathogenic role in leukemia.
    European Journal Of Haematology 03/1998; 60(3):197-201. · 2.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this report, we presented the results that EGCG, the main constituent of the polyphenols present in Japanese green tea inhibited growth of leukemic cell lines of both human and mice. The proliferation of human leukemic cell lines and mouse NFS60 cell line was inhibited by EGCG. Sensitivity of each line to EGCG was different, and more than 50% of DNA systhesis was reduced in all the cell lines in the presence of 50 μM EGCG. On the other hand, normal hematopoietic progenitor cells retained their natural function of supplying mature cells of various lineages in the presence of less than 10 μM EGCG in vitro. Even in the presence of 100 μM EGCG, half the colonies containing all the lineages of cells were developed. All the dead cells of each line showed characteristics of apoptosis, which might be due to inhibition by EGCG of growth factors' signaling. Besides anticarcinogenic activity, EGCG is expected to have a new function for leukemia therapy without side effects.
    Life Sciences 02/1998; · 2.56 Impact Factor
  • Y Asano, Y Niho
    Ryōikibetsu shōkōgun shirīzu. 02/1998;