Y Miyazaki

Kansai Medical University, Moriguchi, Ōsaka, Japan

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Publications (29)83.21 Total impact

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    ABSTRACT: The recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) often develop acute graft-versus-host disease (aGVHD), which is closely related to morbidity and mortality. However, the essential part of the immune responses elicited in aGVHD remains largely unknown. We attempt to determine if peripheral blood dendritic cells (PBDCs) are altered in aGVHD, and find that the number of PBDCs (both myeloid and lymphoid DCs) is significantly decreased. Immunohistochemical staining of the biopsied skin from patients with aGVHD demonstrates that a number of fascin(+) cells with dendritic projections infiltrate the dermis of the skin. Based on these findings, we hypothesize that the PBDCs are recruited to the affected tissues and may thus play important roles in immune responses elicited in aGVHD.
    Bone Marrow Transplantation 06/2004; 33(10):989-96. · 3.54 Impact Factor
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    ABSTRACT: Nephrotic syndrome after hematopoietic stem cell transplantation (HSCT) followed by donor lymphocyte infusion (DLI) has never been described. We report the case of a myelodysplastic syndrome (MDS) patient who developed nephrotic syndrome with membranous nephropathy 18 months after allogeneic HSCT and 4 months after DLI. A 50-year-old woman with MDS underwent allogeneic bone marrow transplantation from her HLA-matched brother. MDS relapsed 55 days after transplantation, donor lymphocytes were infused as adoptive immunotherapy, and complete remission was achieved. Four months after the third DLI, the patient developed nephrotic syndrome with proteinuria up to 9 g/day. Renal biopsy revealed granular deposits of immunoglobulin G along the glomerular basement membrane, and subepithelial electron-dense deposits. A diagnosis of membranous nephropathy was made. For maintenance of the immunotherapeutic effect of DLI, minimum doses of immunosuppressive therapy for decreasing proteinuria were administered, and improvement of nephrotic syndrome and persistent complete remission of MDS were achieved.
    International Journal of Hematology 11/2003; 78(3):262-5. · 1.68 Impact Factor
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    ABSTRACT: An adult patient suffering from G-CSF-resistant very severe aplastic anemia received a cord blood transplantation from a three-loci HLA-mismatched unrelated donor after nonmyeloablative conditioning. Cord blood was infused after conditioning with fludarabine (180 mg/m2) and cyclophosphamide (100 mg/kg). Cyclosporin A and short-term methotrexate were used for prophylaxis against acute GVHD. Engraftment was achieved on day 23, and there was no serious GVHD. A full-donor type T-cell chimerism was obtained by day 30. Normal hematopoiesis and complete chimerism have been maintained 14 months after transplantation.
    [Rinshō ketsueki] The Japanese journal of clinical hematology 09/2003; 44(9):965-7.
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    ABSTRACT: We report the response to, and toxicity of antithymocyte globulin (ATG) treatment in 11 consecutive patients (7 men and 4 women; median age 46 years) with aplastic anemia (AA). Six of the patients had severe disease and 5 had moderate disease; all were treated within one year from diagnosis. The ATG regimen was the initial treatment for 6 patients, but a sequential treatment for the other 5. Cyclosporin A was administered orally 1-3 weeks after the ATG treatment. All patients were assessed for over 6 months (median, 20.4 months); 8 showed a good response, 1 a minimal response, and 2 no response. Disease severity had no influence on the response. In 1 patient, ATG treatment had to be discontinued because of hepatic toxicity. However, adverse reactions were not severe in the other 10 patients. These findings suggest that ATG treatment is a safe and effective therapy for AA.
    [Rinshō ketsueki] The Japanese journal of clinical hematology 08/2000; 41(7):563-7.
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    ABSTRACT: Adult T-cell leukemia (ATL) is associated with human T-cell leukemia virus type 1 (HTLV-1) and is known to be a refractory disease of highly poor prognosis. We describe a case of ATL treated with allogeneic bone marrow transplantation (allo-BMT). The allo-BMT successfully induced complete remission in the patient. Currently, at 24 months post BMT, there has been no evidence of minimal residual disease (MRD) detected by polymerase chain reaction (PCR) assay for the T-cell receptor gamma chain gene. By contrast, PCR analysis demonstrated the reappearance of the cells harboring the integrations of the HTLV-1 proviral DNA 9 months after the BMT. These findings may imply a reversion to the carrier state rather than the recurrence of the leukemia from the MRD. The clinical consequence of our case illustrates that allo-BMT is an effective therapy, at least for achieving longer disease-free survival in ATL.
    International Journal of Hematology 05/2000; 71(3):290-3. · 1.68 Impact Factor
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    ABSTRACT: We examined tissue factor expression on lipopolysaccharide-stimulated endothelial cells and their small vesicles by using specific antibodies and flow cytometry. Tissue factor functional activity was also assessed by activation of factor X. Endothelial cells were stimulated with 10 microg/ml of lipopolysaccharide in M-199/bovine serum albumin. Flow cytometry showed that expression of tissue factor on endothelial cells reached a maximum at 6 hours after stimulation, whereas that on small vesicles reached a maximum after 12 hours. Factor X activation mediated by factor VIIa and tissue factor was observed over a similar time course and was inhibited by the addition of antitissue factor antibody. Immunoelectron microscopy suggested that small vesicles with expression of some tissue factor were produced from the surface of endothelial cells. Our findings thus showed that tissue factor on endothelial cells produced by lipopolysaccharide stimulation was partly released to small vesicles. This may cause disseminated intravascular coagulation and related coagulation disorders.
    Thrombosis Research 10/1998; 91(6):297-304. · 3.13 Impact Factor
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    ABSTRACT: Human platelet glycoprotein Ib/IX complex acts as a receptor for von Willebrand factor. It is widely accepted that glycoprotein Ib is the essential receptor component, but the role of glycoprotein IX is still unclear. We produced a new monoclonal anti-glycoprotein IX antibody (KMP-9) by the hybridoma technique using platelets from a patient with Glanzmann's thrombasthenia. The epitope of KMP-9 was localized to the C-terminal 8 kD fragment of glycoprotein IX using ELISA analysis of polyethylene-pin-synthesized peptides, as well as Western blot analysis of platelets after digestion with N-glycosidase and Staphylococcus aureus V8 protease. KMP-9 partially inhibited high shear stress-induced platelet aggregation, but had no effect on aggregation induced by ristocetin or low shear stress. Its inhibitory effect on high shear stress-induced aggregation was weaker than that of anti-glycoprotein Ib or anti-glycoprotein IIb/IIIa monoclonal antibodies. A 21-mer synthetic peptide (glycoprotein IX L110-G130) inhibited the binding of KMP-9 to platelets. It also competively inhibited the suppression of high shear stress-induced platelet aggregation by KMP-9, but had no direct effect on this aggregation. KMP-9 may be useful to clarify the physiological role of GPIX.
    Thrombosis and Haemostasis 09/1997; 78(2):902-9. · 5.76 Impact Factor
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    ABSTRACT: NNKY5-5, an IgG monoclonal antibody directed against the von Willebrand factor-binding domain of glycoprotein (GP) Ib alpha, induced weak but irreversible aggregation (or association) of platelets in citrate-anticoagulated platelet-rich plasma. This phenomenon was defined as small aggregate formation (SAF). Platelets in hirudin-anticoagulated plasma or washed platelets showed little response to NNKY5-5 alone, but the antibody potentiated aggregation induced by low concentrations of adenosine diphosphate or platelet-activating factor. NNKY5-5 did not induce granule release or intracellular Ca2+ mobilization. However, NNKY5-5 caused tyrosine phosphorylation of a 64-kD protein and activation of a tyrosine kinase, p72syk. An anti-Fc gamma II receptor antibody had no effect on SAF, suggesting that NNKY5-5 activated platelets by interacting with glycoprotein Ib. Fab' fragments of NNKY5-5 did not induce SAF, but potentiated aggregation induced by other agonists. The Fab' fragment of NNKY5-5 induced the activation of p72syk, suggesting that such activation was independent of the Fc gamma II receptor. Cross-linking of the receptor-bound Fab' fragment of NNKY5-5 with a secondary antibody induced SAF. GRGDS peptide, chelation of extracellular Ca2+, and an anti-GPIIb/IIIa antibody inhibited NNKY5-5-induced SAF, but had no effect on 64-kD protein tyrosine phosphorylation or p72syk activations. Various inhibitors, including aspirin and protein kinase C, had no effect on SAF, protein tyrosine phosphorylation, or p72syk activation. In contrast, tyrphostin 47, a potent tyrosine kinase inhibitor, inhibited NNKY5-5-induced SAF as well as tyrosine phosphorylation and p72syk activation. Our findings suggest that binding of NNKY5-5 to GPIb potentiates platelet aggregation by facilitating the interaction between fibrinogen and GPIIb/IIIa through a mechanism associated with p72syk activation and tyrosine phosphorylation of a 64-kD protein.
    Blood 04/1997; 89(5):1590-8. · 9.78 Impact Factor
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    ABSTRACT: Previous studies have demonstrated that a high level of shear stress can produce platelet aggregation without the addition of any agonist. We investigated whether high shear stress could cause both platelet aggregation and shedding of microparticles from the platelet plasma membrane. A coneplate viscometer was used to apply shear stress and microparticle formation was measured by flow cytometry. It was found that microparticle formation increased as the duration of shear stress increased. Both microparticles and the remnant platelets showed the exposure of procoagulant activity on their surfaces. Investigation of the mechanisms involved in shear-dependent microparticle generation showed that binding of von Willebrand factor (vWF) to platelet glycoprotein lb, influx of extracellular calcium, and activation of platelet calpain were required to generate microparticles under high shear stress conditions. Activation of protein kinase C (PKC) promoted shear-dependent microparticle formation. Epinephrine did not influence microparticle formation, although it enhanced platelet aggregation by high shear stress. These findings suggest the possibility that local generation of microparticles in atherosclerotic arteries, the site that pathologically high shear stress could occur, may contribute to arterial thrombosis by providing and expanding a catalytic surface for the coagulation cascade.
    Blood 12/1996; 88(9):3456-64. · 9.78 Impact Factor
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    ABSTRACT: We employed flow cytometry and monoclonal antibodies (MoAb) to study the surface membrane protein of shed particles (small vesicles, SV) that were released from vascular endothelial cells (EC) by agonists such as a Ca ionophore (A23187) and thrombin. After stimulation of EC by A23187, CD9 antigens disappeared entirely from the EC surface in a time- and concentration-dependent manner; they subsequently moved onto the SV surface. Von Willebrand factor (vWF) and P-selectin from Weibel-Palade (W-P) bodies were expressed rapidly on the EC surface after thrombin stimulation, but not on the SV surface. P-selectin may have some effect on maintenance of hemostasis on the EC surface. We demonstrated that the surfaces of SV and EC significantly supported prothrombinase activity and confirmed that A23187-induced SV from EC express binding sites for factors IXa and Xa. These results suggest that the SV are an important factor in a novel controlling mechanism of the coagulation system on the EC surface.
    Thrombosis Research 01/1996; 80(6):451-60. · 3.13 Impact Factor
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    ABSTRACT: To study platelet-derived microparticle generation in diabetes mellitus, we injected alloxan into male Japanese white rabbits. Injection of alloxan induced diabetes, but did not cause any significant change in various biochemical and hematological parameters. However, diabetic rabbits showed a significant elevation of platelet-derived microparticles from 8 weeks after alloxan injection (week 0: 0.45 ± 0.24%; week 8: 1.12 ± 0.61%, p < 0.005). These microparticles are known to have prothrombinase activity, suggesting that they may promote vascular complications in diabetes and may be used as a marker of vascular disease.
    Pathophysiology of Haemostasis and Thrombosis 01/1996; 26(4):228-232. · 2.23 Impact Factor
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    ABSTRACT: We investigated the role of αIIbβ3 in microparticle generation by normal and thrombasthenic platelets stimulated with collagen plus thrombin. Microparticle generation by normal platelets was scarcely inhibited by monoclonal antibodies for glyco-protein lb and glycoprotein IX. Although one monoclonal anti-α αIIbβ3 antibody (NNKY1-32) partly inhibited microparticle generation, 3 other monoclonal anti-α αIIbβ3 antibodies had little effect. However, the combination of 4 monoclonal anti- αIIbβ3 antibodies or treatment with a polyclonal anti- αIIbβ3 antibody significantly inhibited microparticle generation (p < 0.05). Microparticle generation by thrombasthenic platelets also occurred after stimulation with collagen plus thrombin, although at a significantly lower level compared with normal platelets. Monoclonal antibodies for resting αIIbβ3, P-selectin, activated αIIbβ3 and β2-glycoprotein I bound to microparticles from healthy platelets. In contrast, only a monoclonal antibody for β2-glycoprotein I bound to thrombasthenic microparticles. These results suggest that microparticle generation by collagen plus thrombin occurs via two different mechanisms which are dependent and independent of αIIbβ3, respectively. The αIIbβ3-dependent mechanism appears to require activation of αIIbβ3·
    Pathophysiology of Haemostasis and Thrombosis - PATHOPHYSIOL HAEMOST THROMB. 01/1996; 26(1):31-37.
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    ABSTRACT: We investigated the significance of cytokines (soluble interleukin-2 receptor, granulocyte-macrophage colony-stimulating factor, interleukin-6, and interferon-gamma) and CD68-positive microparticles in immune thrombocytopenic purpura. Cytokines were measured by enzyme-linked immunosorbent assay and microparticles were detected by flow cytometry. CD68 expression by histiocytic U937 cells incubated with lipopolysaccharide or cytokines was also assessed in a control study. The level of CD68-positive microparticles was significantly higher in the patients with thrombocytopenia than in normal controls (p < 0.01). The soluble interleukin-2 receptor level was also significantly higher in patients than in controls (p < 0.01), but the other cytokines did not show a significant difference. However, patients with severe thrombocytopenia (platelet count > 20,000/microliters) had significantly higher levels of granulocyte-macrophage colony-stimulating factor and interleukin-6 than the controls (p < 0.05). When opsonized platelets were incubated with activated U937 cells, lipopolysaccharide and granulocyte-macrophage colony-stimulating factor caused an increase of CD68-positive microparticles in the supernatant. These results suggest that granulocyte-macrophage colony-stimulating factor is released by activated T cells in immune thrombocytopenic purpura and activates monocyte/macrophage phagocytosis, resulting in an increase of circulating CD68-positive microparticles and enhanced platelet destruction.
    European Journal Of Haematology 08/1995; 55(1):49-56. · 2.55 Impact Factor
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    ABSTRACT: We investigated the association between low-density lipoprotein (LDL), triglycerides, and platelet activation in 18 patients with hypertension age 41-64 years and 18 with diabetes mellitus aged 43-70 years. Platelet P-selectin positivity and the microparticle level (indicators of activation) were both significantly higher in the diabetics than in healthy controls (P-selectin: 28.0% +/- 7.5% vs. 7.3% +/- 4.2%, P < 0.001; microparticles: 1900 +/- 966 vs. 526 +/- 158/10(4) platelets, P < 0.01). In contrast, there was no significant increase of either parameter in the patients with hypertension. Plasma microparticle levels were also significantly greater in the diabetics with high LDL levels than in those with low LDL levels (2375 +/- 949 vs. 1519 +/- 796/10(4) platelets, P < 0.05), and in those with high rather than low triglyceride levels (2188 +/- 845 vs. 1492 +/- 783/10(4) platelets, P < 0.05). However, platelet positivity for P-selectin was not significantly different between these two subgroups. Microparticle and P-selectin levels both showed no significant difference between the hypertensive patients with high and low LDL or triglyceride levels. These results suggest that platelet-derived microparticles may participate in the development or progression of atherosclerosis in patients with diabetes mellitus.
    Atherosclerosis 08/1995; 116(2):235-40. · 3.71 Impact Factor
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    ABSTRACT: We measured soluble interleukin-2 receptor (sIL-2 R) in serum samples from 57 patients with idiopathic thrombocytopenic purpura (ITP). The sIL-2 R level was significantly increased in the ITP patients (481.3 +/- 378.5 U/ml) compared with controls (176.2 +/- 66.9 U/ml) (p < 0.001), and was significantly higher in 8 patients positive for hepatitis C virus (HCV) antibody positive (1,140.7 +/- 194.3 U/ml) than in 49 HCV-antibody negative patients (378.9 +/- 278.6 U/ml) (p < 0.0001). There was also a significant difference between the HCV-antibody negative ITP patients and the controls (p < 0.01). Elevated sIL-2 R levels correlated with the CD 4/8 ratio (p < 0.05), but not with the platelet count or the level of platelet-associated IgG. The increase of sIL-2 R in ITP may be related to the immunological abnormalities underlying this disease.
    Japanese Journal of Clinical Immunology 02/1995; 18(1):14-9.
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    ABSTRACT: We investigated the association of beta 2-glycoprotein I and P-selectin with platelet-derived microparticles in 48 patients with immune thrombocytopenic purpura and 20 normal controls using two-color flow cytometric analysis. In addition, anticardiolipin antibodies were detected by an enzyme-linked immunosorbent assay. Platelet microparticles from the patients showed a higher positivity for beta 2-glycoprotein I than those from the normal controls (23.1 +/- 15.4% vs. 5.3 +/- 3.1%, p < 0.01), but this positivity was not related to the presence of platelet-associated IgG or to the severity of thrombocytopenia. In the 18 patients with more than 20% P-selectin-positive microparticles, beta 2-glycoprotein I positivity was significantly higher than in the 30 patients with less than 20% P-selectin-positive microparticles (37.1 +/- 20.5% vs. 21.5 +/- 17.3%, p < 0.01). In addition, anticardiolipin antibodies were detected in eight patients, and they had a significantly higher level of beta 2-glycoprotein I-positive microparticles than the patients without such antibodies (42.0 +/- 22.9% vs. 22.6 +/- 18.9%, p < 0.05). Our results suggest that anticardiolipin antibodies activate platelets in immune thrombocytopenic purpura and cause the generation of microparticles rich in beta 2-glycoprotein I and P-selectin. These microparticles may then act to regulate coagulation abnormalities in patients with anticardiolipin antibodies.
    Annals of Hematology 01/1995; 70(1):25-30. · 2.87 Impact Factor
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    ABSTRACT: We investigated the association of 2-glycoprotein I and P-selectin with platelet-derived microparticles in 48 patients with immune thrombocytopenic purpura and 20 normal controls using two-color flow cytometric analysis. In addition, anticardiolipin antibodies were detected by an enzyme-linked immunosorbent assay. Platelet microparticles from the patients showed a higher positivity for 2-glycoprotein I than those from the normal controls (23.115.4% vs. 5.33.1%, p 2-glycoprotein I positivity was significantly higher than in the 30 patients with less than 20% P-selectin-positive microparticles (37.120.5% vs. 21.517.3%, p 2-glycoprotein I-positive microparticles than the patients without such antibodies (42.022.9% vs. 22.618.9%, p 2-glycoprotein I and P-selectin. These microparticles may then act to regulate coagulation abnormalities in patients with anticardiolipin antibodies.
    Annals of Hematology 12/1994; 70(1):25-30. · 2.87 Impact Factor
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    ABSTRACT: We investigated the association of amyloid beta-protein precursor (APP) and platelet derived microparticles in 20 normal controls and 91 patients with various diseases causing a thrombotic tendency. Compared with the controls, the mean percentage of APP-positive microparticles was significantly greater in the patients with cerebral infarction (39.1 +/- 17.7%, p < 0.001), diabetes (31.1 +/- 12.6%, p < 0.001), and uremia (30.1 +/- 14.7%, p < 0.01), but not in those with hypertension (8.2 +/- 6.3%, p = NS). Sixteen patients with cerebral infarction, 20 with diabetes, and 11 with uremia had microparticles with very high APP levels. In normal controls, 7.2 +/- 3.7% of the microparticles were positive for P-selectin, while the percentage in cerebral infarction, diabetes, uremia, and hypertension was respectively 43.5 +/- 15.1%, 40.0 +/- 12.8%, 31.8 +/- 12.2%, and 11.6 +/- 7.3%. There was a significant correlation between P-selectin and APP positivity of microparticles. Our results suggest that microparticle APP may have a regulatory influence on coagulation abnormalities.
    Thrombosis and Haemostasis 10/1994; 72(4):519-22. · 5.76 Impact Factor
  • European Journal Of Haematology 05/1994; 52(4):254-5. · 2.55 Impact Factor
  • Transfusion 03/1994; 34(2):186-7. · 3.53 Impact Factor