Masahiro Masuya

Michiana Hematology Oncology, Indiana, Pennsylvania, United States

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Publications (92)312.5 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The spleen is not believed to contribute to hematopoiesis in healthy adults. However, several reports have demonstrated that the spleen in adults contains a large number of hematopoietic stem/progenitor cells (HSCs). Although splenectomy increases platelet and leukocyte counts, the effects of splenectomy on circulating HSCs have not been elucidated. In this study, we evaluated the association between the number of circulating HSCs and splenectomy in patients with hepatitis C virus (HCV)-associated liver cirrhosis (LC). In 48 patients with various stages of HCV-associated chronic liver disease (CLD) and seven patients with LC who underwent splenectomy, and 10 healthy volunteers, we determined the numbers of circulating CD34(+) cells and colony forming unit-culture by flow cytometry and methylcellulose culture, respectively. Plasma stromal cell-derived factor-1α (SDF-1α) concentrations were measured using an enzyme-linked immunosorbent assay. The numbers of circulating CD34(+) cells and colony forming unit-culture decreased but the plasma SDF-1α concentration increased with the progression of liver disease. There was an inverse correlation between the number of circulating HSCs and the plasma SDF-1α concentration. The numbers of circulating HSCs and platelets were determined before and after splenectomy in seven patients with LC. In these patients, the numbers of circulating HSCs and platelets increased significantly after splenectomy and the enhancing effect persisted for a long time. Our data suggest that the spleen plays an important role in modulating HSC dynamics in patients with HCV-associated CLD. Our results also imply that splenectomy may improve liver function in patients with LC.
    Hepatology Research 02/2014; · 2.07 Impact Factor
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    ABSTRACT: Recent studies have shown that monocytes possess pluripotent plasticity. We previously reported that monocytes could differentiate into hepatic stellate cells. Although stellate cells are also present in the pancreas, their origin remains unclear. An accumulation of enhanced green fluorescent protein (EGFP)(+)CD45(-) cells was observed in the pancreases and livers of chimeric mice, which were transplanted with a single hematopoietic stem cell isolated from EGFP-transgenic mice and treated with carbon tetrachloride (CCl4). Because the vast majority of EGFP(+)CD45(-) cells in the pancreas expressed stellate cell-associated antigens such as vimentin, desmin, glial fibrillary acidic protein, procollagen-I, and α-smooth muscle actin, they were characterized as pancreatic stellate cells (PaSCs). EGFP(+) PaSCs were also observed in CCl4-treated mice adoptively transferred with monocytes but not with other cell lineages isolated from EGFP-transgenic mice. The expression of monocyte chemoattractant protein-1 (MCP-1) and angiotensin II (Ang II) increased in the pancreas of CCl4-treated mice and their respective receptors, C-C chemokine receptor 2 (CCR2) and Ang II type 1 receptor (AT1R), were expressed on Ly6C(high) monocytes isolated from EGFP-transgenic mice. We examined the effect of an AT1R antagonist, irbesartan, which is also a CCR2 antagonist, on the migration of monocytes into the pancreas. Monocytes migrated toward MCP-1 but not Ang II in vitro. Irbesartan inhibited not only their in vitro chemotaxis but also in vivo migration of adoptively transferred monocytes from peripheral blood into the pancreas. Irbesartan treatment significantly reduced the numbers of EGFP(+)F4/80(+)CCR2(+) monocytic cells and EGFP(+) PaSCs in the pancreas of CCl4-treated chimeric mice receiving EGFP(+) bone marrow cells. A specific CCR2 antagonist RS504393 inhibited the occurrence of EGFP(+) PaSCs in injured mice. We propose that CCR2(+) monocytes migrate into the pancreas possibly via the MCP-1/CCR2 pathway and give rise to PaSCs.
    PLoS ONE 01/2014; 9(1):e84889. · 3.73 Impact Factor
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    ABSTRACT: Oncogenic transformation requires unlimited self-renewal. Currently it remains unclear whether a normal capacity for self-renewal is required for acquiring an aberrant self-renewal capacity. Our results in a new conditional transgenic mouse showed that a Mixed Lineage Leukemia (MLL) fusion oncogene, MLL-ENL, at an endogenous-like expression level led to leukemic transformation selectively in a restricted subpopulation of hematopoietic stem cells (HSCs) through upregulation of Promyelocytic leukemia zinc finger (Plzf). Interestingly, forced expression of Plzf itself immortalized HSCs and myeloid progenitors in vitro without upregulation of Hoxa9/Meis1, which are well-known targets of MLL fusion proteins, while its mutant lacking the BTB/POZ domain did not. In contrast, depletion of Plzf suppressed the MLL-fusion-induced leukemic transformation of HSCs in vitro and in vivo. Gene expression analyses of human clinical samples showed that a subtype of PLZF-high MLL-rearranged myeloid leukemia cells was closely associated with the gene expression signature of HSCs. These findings suggested that MLL fusion protein enhances the self-renewal potential of normal HSCs to develop leukemia, in part through a Plzf-driven self-renewal program.
    Blood 07/2013; · 9.78 Impact Factor
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    ABSTRACT: OBJECTIVES: Invasive fungal diseases (IFDs) are life-threatening events in patients with haematologic disorders, and the spectrum of the aetiological pathogens continues to expand. This study aimed to evaluate the clinical utility of a panfungal polymerase chain reaction (PCR) assay for the management of IFDs in such patients. METHODS: We prospectively analysed 273 consecutive blood samples from 64 risk episodes in 51 patients with haematologic disorders at high risk for IFD who were treated at our hospital between April 2007 and October 2010. RESULTS: PCR-positive results were obtained in 18 of 64 risk episodes (35.3%). IFD was documented in 14 episodes (21.9%, 9 probable IFDs and 5 possible IFDs) according to the revised criteria of the European Organization for Research and Treatment of Cancer/Mycoses Study Group. PCR was positive in all of these 14 episodes, and in 4 of the 50 episodes with no IFD category. Sensitivity, specificity, positive predictive value, and negative predictive value of our assay were 100%, 92%, 78%, and 100%, respectively. A considerable number of fungi (44.4%) that are less common than Aspergillus and Candida species were positive by PCR. Molecular diagnoses of Cunninghamella species, Aspergillus ustus, Fusarium species, Scedosporium apiospermum, Rhodotorula species, and Rhizopus species were beneficial in selecting suitable treatments. CONCLUSIONS: Our panfungal PCR approach allows for the highly sensitive and specific detection and identification of a wide spectrum of fungal pathogens, which provides indispensable information for managing IFDs, especially refractory or breakthrough IFDs during antifungal therapy in high-risk patients with haematologic disorders. © 2013 John Wiley & Sons A/S.
    European Journal Of Haematology 01/2013; · 2.55 Impact Factor
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    ABSTRACT: We herein report the case of a 77-year-old woman who developed acute thrombocytopenia during the 23rd cycle of modified FOLFOX therapy. She developed a hypersensitivity reaction with nasal bleeding. The chemotherapy infusion was immediately discontinued. The patient's symptoms resolved with discontinuation of chemotherapy and the administration of supportive therapy. A complete blood count showed severe thrombocytopenia, and oxaliplatin-induced thrombocytopenia was diagnosed. The patient was admitted to the hospital, and the thrombocytopenia was corrected with a platelet transfusion followed by prednisolone. She was discharged after one week without requiring additional platelet transfusions. With the widespread use of oxaliplatin, the risk of oxaliplatin-induced acute thrombocytopenia should be considered an acute onset hematological emergency.
    Internal Medicine 01/2013; 52(5):611-5. · 0.97 Impact Factor
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    ABSTRACT: T cell precursors are an attractive target for adoptive immunotherapy. Here, we examined regulation of human early T lymphopoiesis by human bone marrow stromal cells to explore in vitro manipulation of human T cell precursors in a human-only coculture system. Generation of CD7(+)CD56(-)cyCD3(-) proT cells from human hematopoietic progenitors on telomerized human bone marrow stromal cells was enhanced by stem cell factor (SCF), flt3 ligand (Flt3L) and thrombopoietin (TPO), but these stimulatory effects were suppressed by interleukin-3. Expression of Notch ligands Delta-1 and -4 on stromal cells additively promoted T cell differentiation into the CD7(+)cyCD3(+)preT cell stage, while cell growth was strongly inhibited. By combining these coculture systems, we found that initial coculture with telomerized stromal cells in the presence of SCF, Flt3L and TPO, followed by coculture on Delta-1- and -4-coexpressing stromal cells led to a higher percentage and number of preT cells. Adoptive immunotherapy using peripheral blood T cells transduced with a tumor antigen-specific T cell receptor (TCR) is a promising strategy but has several limitations such as the risk of forming a chimeric TCR with the endogenous TCR. We demonstrated that incubation of TCR-transduced hematopoietic progenitors with the combination of coculture systems gave rise to CD7(+)TCR(+)CD3(+)CD1a(-) T cell precursors that rapidly proliferated and differentiated under the culture condition to induce mature T cell differentiation. These data show the regulatory mechanism of early T lymphopoiesis on human stromal cells and the potential utility of engineered human stromal cells to manipulate early T cell development for clinical application.
    Experimental hematology 12/2012; · 3.11 Impact Factor
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    ABSTRACT: The regulation of human early lymphopoiesis remains unclear. B- and T-lineage cells cannot develop simultaneously with conventional stromal cultures. Here we show that telomerized human bone marrow stromal cells supported simultaneous generation of CD19(+) CD34(lo/-) CD10(+) cyCD79a(+) CD20(+/-) VpreB(-) pro-B cells and CD7(+) CD34(+) CD45RA(+) CD56(-) cyCD3(-) early T/Natural Killer (NK) cell precursors from human haematopoietic progenitors, and the generation of both lymphoid precursors was promoted by flt3 ligand (flt3L). On the other hand, stem cell factor or thrombopoietin had little or no effect when used alone. However, both acted synergistically with flt3L to augment the generation of both lymphoid precursors. Characteristics of these lymphoid precursors were evaluated by gene expression profiles, rearrangements of IgH genes, or replating assays. Similar findings were observed with primary human bone marrow stromal cells. Notably, these two lymphoid-lineage precursors were generated without direct contact with stromal cells, indicating that early B and T/NK development can occur, at least in part, by stromal cell-derived humoral factors. In serum-free cultures, flt3L elicited similar effects and appeared particularly important for B cell development. The findings of this study identified the potential of human bone marrow stromal cells to support human early B and T lymphopoiesis and a principal role for flt3L during early lymphopoiesis.
    British Journal of Haematology 03/2012; 157(6):674-86. · 4.94 Impact Factor
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    ABSTRACT: Interstitial lung diseases (ILD) are characterized by progressive interstitial pulmonary fibrosis and a decline in lung function. Fibrocytes are bone marrow-derived mesenchymal progenitor cells that may play a role in the pathogenesis of pulmonary fibrosis. Circulating fibrocyte numbers have been correlated with the prognosis of patients with idiopathic pulmonary fibrosis. The aim of the present study was to evaluate the relationship between circulating fibrocytes, and parameters of disease activity and progression in several groups of patients with ILD. The study population comprised 41 patients with ILD and seven healthy control subjects. Circulating CD45(+) collagen-I(+) fibrocytes were evaluated by flow cytometry. The number of circulating fibrocytes was significantly increased in all patients with ILD and particularly in patients with idiopathic interstitial pneumonitis and interstitial pneumonitis associated with collagen vascular disease as compared with healthy control subjects. The numbers of circulating fibrocytes were significantly correlated with pulmonary function test parameters and with serum levels of sialylated carbohydrate antigen, a marker of disease activity. Temporal changes in circulating fibrocyte numbers were evaluated in two patients, and the results suggested that these changes correlated with the activity of ILD. The results from this study provide further evidence for the role of circulating fibrocytes in fibrotic lung diseases.
    Respirology 03/2012; 17(4):693-8. · 2.78 Impact Factor
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    ABSTRACT: Sepsis caused by the bacterial contamination of blood products is a major infection risk associated with blood transfusion. Diversion of the initial 25 mL of blood and prestorage leukoreduction were implemented in Japan in 2007 for all donated blood products. We assessed the efficacy of these new collection procedures in preventing bacterial contamination of red blood cell (RBC) concentrates. Broad-range 16S ribosomal RNA polymerase chain reaction was used to determine bacterial contamination in segment samples of RBCs before and after implementation of the new collection procedures. To evaluate whether these new procedures reduced bacterial contamination, we compared bacterial contamination rates of blood samples from diversion pouches with those of segment samples from the same donor's RBCs. The rate of bacterial contamination of RBCs before implementation of the new collection procedures was 1.27%. Most of the isolated bacteria were Staphylococcus epidermidis or Propionibacterium acnes. After implementation, this rate was significantly reduced to 0.10%. Of the 233 whole blood samples obtained from the Mie Red Cross Blood Center, 1.72% of blood samples from diversion pouches were contaminated, but no bacterial contamination was detected in segment samples from the same donor's RBCs after prestorage leukoreduction. The new collection procedure significantly reduced bacterial contamination of RBC concentrates.
    Transfusion Medicine 12/2011; 21(6):365-70. · 1.26 Impact Factor
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    ABSTRACT: The BCR-ABL1 induces chronic myelogenous leukemia (CML) and Ph+ acute lymphoblastic leukemia (ALL). Recent studies revealed high ratios of loss of the IKZF1 gene which encodes IKAROS in BCR-ABL1+ ALL and lymphoblastic crisis (LBC) of CML. However, little is known about the cooperativity between the aberrant IKAROS and BCR-ABL1 in primary human hematopoietic cells. We investigated the effects of expression of BCR-ABL1 and/or IK6, a natural dominant negative isoform of IKAROS, on proliferation and differentiation of human CD34+ cord blood cells with or without human bone marrow-derived stromal cells which support early B cell differentiation. Cell proliferation was remarkably enhanced by co-expression of BCR-ABL1 and IK6, with reduced expression of glycophorin A and increased expression of CD41, especially on stromal cells, compared with expression of BCR-ABL1 alone that resulted in expansion of erythroid progenitors. Interestingly, p190BCR-ABL1 showed higher dependency on stromal cells to stimulate cell growth with IK6, than p210BCR-ABL1. Furthermore, the cooperation was found to depend on direct cell adhesive interaction of hematopoietic progenitors with stromal cells. These findings suggest that IK6 and BCR-ABL1 synergistically contribute to leukemogenesis in human bone marrow stromal microenvironment, and may provide a clue to elucidate the mechanisms of leukemogenesis of Ph+ ALL and CML-LBC.
    International Journal of Oncology 09/2011; 40(1):53-62. · 2.66 Impact Factor
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    ABSTRACT: We previously reported that hepatic stellate cells (HpSCs) are of hematopoietic origin in liver injury. However, the immediate precursors of HpSCs remain unknown. This study was conducted to elucidate whether terminally differentiated blood cells can differentiate into HpSCs. We adoptively transferred a variety of cells isolated from enhanced green fluorescent protein (EGFP)-transgenic mice into carbon tetrachloride (CCl(4))-treated nontransgenic mice twice weekly for 2 weeks. We examined the presence of EGFP(+) HpSCs in the injured liver using immunofluorescence analysis. Monocytes, neutrophils, eosinophils, B cells, or T cells from EGFP mice were transferred into CCl(4)-treated mice. Thirty percent of EGFP(+) cells in the livers of mice given Ly6C(high)c-kit(-) monocytes were negative for CD45, but were positive for glial fibrillary acidic protein, desmin, CD146, ADAMTS13, and α-smooth muscle actin, well-known markers of HpSCs. EGFP(+)CD45(-) cells were predominantly positive for glial fibrillary acidic protein. Although 48% of EGFP(+) cells were positive for procollagen type I, half of them were CD45(-). In the livers of mice given neutrophils, eosinophils, B cells, or T cells, all of the EGFP(+) cells were CD45(+). The majority of EGFP(+) cells in the nonparenchymal cell fraction purified from the livers of mice given Ly6C(high)c-kit(-) monocytes contained lipid droplets and were positive for glial fibrillary acidic protein, desmin, ADAMTS13, and procollagen type I. When Ly6C(+) monocyte-depleted peripheral blood total nucleated cells were adoptively transferred into CCl(4)-treated mice, we found no EGFP(+)CD45(-) cells in the liver. These results suggest that Ly6C(+) monocytes can become HpSCs in the injured liver.
    Experimental hematology 06/2011; 39(9):934-46. · 3.11 Impact Factor
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    ABSTRACT: Targeted disruption of the Fli1 gene results in embryonic lethality. To dissect the roles of functional domains in Fli1, we recently generated mutant Fli1 mice that express a truncated Fli1 protein (Fli1(ΔCTA)) that lacks the carboxy-terminal regulatory (CTA) domain. Heterozygous Fli1(ΔCTA) mice are viable, while homozygous mice have reduced viability. Early postnatal lethality accounts for 30% survival of homozygotes to adulthood. The peripheral blood of these viable Fli1(ΔCTA)/Fli1(ΔCTA) homozygous mice has reduced platelet numbers. Platelet aggregation and activation were also impaired and bleeding times significantly prolonged in these mutant mice. Analysis of mRNA from total bone marrow and purified megakaryocytes from Fli1(ΔCTA)/Fli1(ΔCTA) mice revealed downregulation of genes associated with megakaroyctic development, including c-mpl, gpIIb, gpIV, gpIX, PF4, NF-E2, MafG, and Rab27B. While Fli1 and GATA-1 synergistically regulate the expression of multiple megakaryocytic genes, the level of GATA-1 present on a subset of these promoters is reduced in vivo in the Fli1(ΔCTA)/Fli1(ΔCTA) mice, providing a possible mechanism for the impared transcription observed. Collectively, these data showed for the first time a hemostatic defect associated with the loss of a specific functional domain of the transcription factor Fli1 and suggest previously unknown in vivo roles in megakaryocytic cell differentiation.
    Molecular and cellular biology 11/2010; 30(21):5194-206. · 6.06 Impact Factor
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    ABSTRACT: To investigate whether a drug interaction exists between bortezomib and the cytochrome P450 (CYP) 3A4 inhibitor itraconazole and/or the CYP2C19 inhibitor lansoprazole that results in increased severity of bortezomib-induced peripheral neuropathy and thrombocytopenia. Retrospective medical record review. Hematology-oncology ward of a university-affiliated hospital in Japan. Six adults with relapsed multiple myeloma who received intravenous bortezomib plus oral dexamethasone as the first course of a 21-day cycle between July 2007 and December 2008. Four of the six patients were treated concomitantly with itraconazole or lansoprazole: two with itraconazole, one with lansoprazole, and one with both itraconazole and lansoprazole. Using the National Cancer Institute's Common Terminology Criteria for Adverse Events, we identified the presence and graded the severity of peripheral neuropathy and thrombocytopenia before and during each patient's first 21-day course of bortezomib plus dexamethasone therapy. All three patients who received itraconazole experienced new or worsening peripheral neuropathy; they also experienced grade 4 thrombocytopenia. The patient who received lansoprazole alone, as well as the two patients who did not receive itraconazole or lansoprazole, had no changes in either adverse effect. We also evaluated the relationship between peripheral neuropathy and bortezomib plus dexamethasone therapy by using the Naranjo adverse drug reaction probability scale, and a probable relationship was found. We further assessed whether a drug interaction between bortezomib and itraconazole and/or lansoprazole had occurred involving the CYP3A4 and/or the CYP2C19 pathways, respectively-resulting in increased severity of the bortezomib-induced peripheral neuropathy and thrombocytopenia-by using the Horn drug interaction probability scale. We found that the occurrence of this drug interaction was strongly supported. CONCLUSIONs: Itraconazole appears to exacerbate peripheral neuropathy and thrombocytopenia induced by bortezomib; however, the mechanism of this drug interaction is unknown. Clinicians should closely monitor for bortezomib-induced adverse effects when itraconazole, or any other potent CYP3A4 inhibitor, is administered concomitantly with bortezomib.
    Pharmacotherapy 07/2010; 30(7):661-5. · 2.31 Impact Factor
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    ABSTRACT: This study aimed to assess the clinical utility of PCR for the analysis of bacteria and fungi from blood for the management of febrile neutropenic patients with hematologic malignancies. Using a PCR system able to detect a broad range of bacteria and fungi, we conducted a prospective pilot study of periodic analyses of blood from patients following intensive chemotherapy. When fever occurred, it was treated with empirical antibiotic therapy, basically without knowledge of the PCR results. In 23 febrile episodes during the neutropenic period, bacteria were detected by PCR in 11 cases, while the same species were identified by blood culture in 3 cases. In 10 out of 11 PCR-positive cases, fever could be managed by empirical therapy. In the empirical-therapy-resistant case, the identification of Stenotrophomonas maltophilia by PCR led to improvement of fever. No fungi were detected by PCR in febrile cases, while Aspergillus fumigatus was detected in one afebrile patient, several days before a clinical diagnosis was made. In subsequent sporadic PCR analyses in 15 cases of febrile neutropenia, bacteria were detected by both PCR and blood culture in 7 cases and by PCR alone in 6. Fungi were not detected. While fever was improved by empirical therapy in 12 out of the 13 PCR-positive cases, the identification of Pseudomonas aeruginosa by PCR in one therapy-resistant case contributed to the successful treatment of persistent fever. Our results indicate that PCR analysis of bacteria from blood provides essential information for managing empirical-therapy-resistant febrile neutropenia.
    Journal of clinical microbiology 06/2010; 48(6):2030-6. · 4.16 Impact Factor
  • Transfusion Medicine 05/2010; 20(5):358-60. · 1.26 Impact Factor
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    ABSTRACT: A 30-year-old Brazilian man hospitalized with AIDS developed a high-grade fever. Neither culture studies nor radiological examinations revealed the cause; small yet highly intense signals in the basal ganglia were detected upon gadolinium (Gd)-enhanced T1-weighted magnetic resonance imaging (MRI) of the head. This finding was equivocal at that time but obviously abnormal for his age. A week later, he developed a movement disorder in his right arm, speech apraxia, and a worsening disturbance of consciousness. Repeated Gd-enhanced T1-weighted MRI demonstrated incredible changes in the brain; enhanced lesions in the basal ganglia deteriorated over time, multiple nodular and ring-enhanced lesions were observed in almost the entire brain. A diagnosis of toxoplasma encephalitis (TE) was confirmed by the detection of Toxoplasma gondii DNA in the cerebrospinal fluid. After initiation of intravenous trimethoprim-sulfamethoxazole (TMP-SMX; 10 mg/kg/day of TMP and 50 mg/kg/day of SMX) treatment, his symptoms and radiological findings improved dramatically. Our case suggests that high-intensity signals seen in the basal ganglia of a Gd-enhanced T1-weighted MRI, even at the preclinical stage, is indicative of TE. Because the use of MRI in general has become more widespread, it is predicted that preclinical lesions of TE will be found in various clinical settings more frequently.
    Journal of Infection and Chemotherapy 04/2010; 16(2):135-8. · 1.55 Impact Factor
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    ABSTRACT: A 46-year-old Japanese man was admitted to our hospital because of prolonged fever. Laboratory examination demonstrated leukopenia, thrombocytopenia, marked liver dysfunction, and elevation of serum ferritin. A bone marrow examination showed several hemophagocytic macrophages, and a diagnosis of hemophagocytic syndrome was made. He was treated using HLH-94 protocol, and his clinical symptoms and laboratory data were rapidly improved. After 5 weeks, fever and liver dysfunction reappeared. A repeat bone marrow examination demonstrated that 28.4% of marrow nucleated cells were atypical lymphocytes, which were positive for CD2, CD7, CD16, CD56, and HLA-DR. Clonality of these proliferating NK cells was confirmed by an analysis of EB virus terminal repeat sequence and cytogenetic analysis, and final diagnosis of aggressive NK-cell leukemia was made. After induction chemotherapy consisting of dexamethasone, etoposide, ifosfamide, and L-asparaginase, the patient achieved partial remission. He received allogeneic peripheral blood stem cell transplantation from his one locus mismatched son, and is alive with no evidence of disease 20 months after transplantation.
    [Rinshō ketsueki] The Japanese journal of clinical hematology 04/2010; 51(4):258-63.
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    ABSTRACT: Although the anticancer activities of histone deacetylase (HDAC) inhibitors have been studied, a role for HDAC in normal hematopoiesis has not been clearly defined. Previous studies have shown that the potent HDAC inhibitor FK228 stimulates interleukin (IL)-3-mediated erythropoiesis. Here, we examined whether the widely used valproic acid (VPA) affects megakaryopoiesis as well as erythropoiesis. CD34(+) cells were incubated in serum-free or serum-containing cultures with cytokines, with or without VPA. In the serum-free cultures containing IL-3+stem cell factor (SCF), VPA significantly increased generation of CD61(+)GPA(-) megakaryocytic and a CD61(+)GPA(+) mixture of megakaryocytic and erythroid precursors from CD34(+) hematopoietic precursors at a pharmacological concentration (100 microg/mL). The increase in generation of megakaryocytic and erythroid precursors by VPA was confirmed by replating cultured cells with thrombopoietin+SCF and erythropoietin+SCF, respectively. VPA was as potent as FK228. In cultures with granulocyte-macrophage colony-stimulating factor+SCF, where CD61(-)GPA(+) erythroid precursors were mostly developed, VPA mainly enhanced the generation of CD61(-)GPA(+) erythroid precursors. In serum-containing cultures, only low numbers of CD61(+) or GPA(+) cells were developed with IL-3+SCF. Nevertheless, a substantial number of these cells were generated with VPA. Furthermore, these stimulating effects of VPA were observed by incubating CD34(+) cells from patients with myelodysplastic syndrome. Quantitative reverse transcription polymerase chain reaction showed that VPA enhanced GATA-2, but not GATA-1, messenger RNA expression with IL-3+SCF. These results indicate a novel role for VPA in enhancing the potential of IL-3 to stimulate megakaryopoiesis as well as erythropoiesis and suggest a new therapeutic approach of epigenetic therapy for hematological disease.
    Experimental hematology 04/2010; 38(8):685-95. · 3.11 Impact Factor
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    Takanori Abe, Masahiro Masuya, Makio Ogawa
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    ABSTRACT: To develop an efficient method for single hematopoietic stem cell (HSC) transplantation for high-level hematopoietic engraftment. We combined single-cell sorting with short-term culture of putative HSCs. Mouse bone marrow cells that had been highly enriched for HSCs were individually deposited into a 96-well culture plate and incubated in the presence of mouse c-kit ligand and either mouse interleukin-11 or human recombinant granulocyte colony-stimulating factor. One week later, the resulting clones of cells were individually transplanted into lethally irradiated recipients. We also carried out time-course analysis of proliferation of the individual clones. Finally, we used micromanipulation of the paired progenies of the single cells and studied self-renewal and differentiation potentials of HSCs again in combination with transplantation. There was a correlation between clone size at day 7 of culture and engraftment at 2 months post-transplantation. Small clones, such as those consisting of <15 cells, often showed high-level multilineage engraftment, while clones consisting of > or =40 cells showed very low levels of engraftment. Daily observation of cell divisions of individual clones revealed that some HSCs are in the G(0) state for as long as 1 week, despite the presence of permissive cytokines. Studies using micromanipulation of paired progenies documented the ability of an HSC to generate two HSCs, as well as asymmetric cell divisions. Single-cell sorting combined with short-term culture of individual putative HSCs provides an efficient method for single HSC transplantation. Analyses of the kinetics of individual HSCs provided direct evidence for HSC cell-cycle dormancy, self-renewal, and expansion.
    Experimental hematology 03/2010; 38(7):603-8. · 3.11 Impact Factor
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    ABSTRACT: Autologous peripheral blood stem cell transplantation (auto-PBSCT) is considered the standard therapy for younger patients with multiple myeloma, however, survival curve doesn't reach plateau. On the other hand, allogeneic reduced-intensity stem cell transplantation (RIST) with graft-versus-myeloma (GVM) effects is expected to be the curable therapy. We had three cases received RIST (one case as a salvage therapy for relapse after tandem auto-PBSCT, and two cases as an intentional RIST after achieving partial response by auto-PBSCT). All of three cases relapsing or progressing after RIST showed disease type of plasmacytoma without plasma cells in the bone marrow. That may be because conditioning regimen doesn't include total body irradiation, or GVM is ineffective in plasmacytoma, but effective in bone marrow. Here, we report clinical course of these three cases with some consideration.
    [Rinshō ketsueki] The Japanese journal of clinical hematology 05/2009; 50(4):289-94.

Publication Stats

1k Citations
312.50 Total Impact Points

Institutions

  • 2009–2011
    • Michiana Hematology Oncology
      Indiana, Pennsylvania, United States
  • 1992–2011
    • Mie University
      • • Department of Hematology and Oncology
      • • Second Department of Internal Medicine
      Tsu-shi, Mie-ken, Japan
  • 2003–2010
    • Medical University of South Carolina
      • Department of Pathology and Laboratory Medicine (College of Medicine)
      Charleston, SC, United States
  • 2007
    • Mie-chuo Medical Center
      Matsusaka, Mie, Japan
  • 2004
    • Georgia Health Sciences University
      • Department of Neurology
      Augusta, GA, United States