44 research outputs found
Size Effect of Hydroxide Nanobuilding Blocks and Nonionic Block Copolymer Templates on the Formation of Ordered Mesoporous Structures
The use of precrystallized nanoparticles as nanobuilding blocks (NBBs) is a promising way to obtain mesoporous materials with crystalline walls. In this study, the size effects of both hydroxide NBBs and nonionic block copolymer (BCP) templates on the formation of ordered mesostructures are investigated. The diameter of layered nickel hydroxide NBBs was controlled at the sub-2 nm scale by an epoxidemediated alkalinization process. Commercially available nonionic BCPs (gyration radii in the range of 11.9−43.9 Å) were used. Mesoperiodic structures were formed by the evaporation-induced self-assembly process. A proper size combination of hydroxide NBBs, smaller than 12.5 Å, and BCPs, larger than 19.9 Å, is shown to be necessary to form ordered mesostructures.The present work is partially supported by JSPS KAKENHI Grant Number JP20K15368 and Core-to-Core Program, MEXT Leading Initiative for Excellent Young Researchers, the Foundation for the Promotion of Ion Engineering, and the Izumi Science and Technology Foundation (2019-J-112)
再生不良性貧血と低リスクMDS患者におけるGPIアンカー型膜タンパク欠損T細胞の意義 : 骨髄不全の免疫学的病態について
取得学位 : 博士(保健学), 学位授与番号 : 医博甲第2189号 , 学位授与年月日 : 平成23年3月22日, 学位授与大学 : 金沢大学, 審査結果の報告日 : 平成23年2月10
Interconnection of organic–inorganic hybrid nano-building blocks towards thermally robust mesoporous structures
The use of organic–inorganic hybrid nanoparticles will enable a control of the characteristics of both the nanoparticles and constructed fine structures. In this study, we report the synthesis of acrylate-intercalated layered manganese, cobalt, and nickel hydroxide nanoparticles and their assembly into ordered mesoporous structures. Polymerization of the intercalated acrylates takes place by means of a radical initiator. The formed organic network improved the thermal stability of the layered hydroxides, which results in thermally robust mesoporous structures. Additionally, it is found that the polymerization can be initiated and progressed at 200 °C without any initiators for the layered nickel hydroxide system. This allows for the scalable solid-state thermal polymerization of intercalated acrylates and the formation of thermally robust hierarchically ordered meso/macroporous powders as well as mesoporous films. The electrochemical characterization reveals that the thermally robust mesoporous films having regulated mesopores allow for the effective diffusion of molecules/solvent compared with the films having collapsed mesoporous structures.The present work is partially supported by JSPS KAKENHI Grant Number JP20K15368, JSPS Core-to-Core Program, MEXT Leading Initiative for Excellent Young Researchers, the Foundation for the Promotion of Ion Engineering, International Network on Polyoxometalate Science at Hiroshima University, and the Izumi Science and Technology Foundation (2019-J-112)
Preemptive therapy of human herpesvirus-6 encephalitis with foscarnet sodium for high-risk patients after hematopoietic SCT
金沢大学医薬保健研究域医学系Human herpesvirus-6 (HHV-6) is a major cause of limbic encephalitis with a dismal prognosis after allogeneic hematopoietic SCT (HSCT). A prospective, multicenter study was conducted to assess the safety and efficacy of preemptive therapy with foscarnet sodium (PFA) for the prevention of HHV-6 encephalitis. Plasma HHV-6 DNA was measured thrice weekly from day 7 until day 36 after umbilical cord blood transplantation (UCBT) or HSCT from HLA-haploidentical relatives. PFA, 90 mg/kg/day, was started when HHV-6 DNA exceeded 5 × 102 copies/mL. Mild and transient adverse events were associated with PFA in 7 of 8 patients. Twelve of 15 UCBT recipients became positive for HHV-6 DNAemia, defined by greater than 1 × 102 copies/mL of HHV-6 DNA in plasma. The virus exceeded 5 × 102 copies/mL in seven patients, whereas none of the five HLA-haploidentical HSCT recipients became positive. One patient developed mild limbic encephalitis just after initial PFA administration. Preemptive PFA therapy is safe, but as HHV-6 DNAemia can abruptly develop before neutrophil engraftment in UCBT recipients, prophylactic PFA administration from day 7 or earlier after UCBT may be needed. © 2011 Macmillan Publishers Limited All rights reserved
Safety of pre-engraftment prophylactic foscarnet administration after allogeneic stem cell transplantation
Human herpesvirus-6 (HHV-6) is a major cause of limbic encephalitis with a dismal prognosis after allogeneic hematopoietic stem cell transplantation (SCT). Because our previous trial of preemptive therapy with foscarnet sodium (phosphonoformic acid; PFA) failed to prevent HHV-6 encephalitis, we conducted a prospective study to examine the safety of prophylactic PFA administration and elucidate the changes in the plasma HHV-6 DNA levels in the early post-SCT period. Plasma HHV-6 DNA was measured thrice weekly from day 6. PFA, 90mg/kg/day, was administered from days 7 to 21 after bone marrow or peripheral blood SCT and to day 25 after umbilical cord blood transplantation. Of the 10 patients enrolled, 2 dropped out of the study, 1 because of early death, and 1 with a low glomerular filtration rate. Grade 3 or greater adverse events occurred in 9 of the 10 prophylactic PFA patients and in 7 of the 10 control patients who had clinical backgrounds similar to the study subjects and underwent SCT during the same period. Neurological disorders developed in none of the study subjects but in 4 of the 10 control patients, including 2 with HHV-6 encephalitis. HHV-6 reactivation occurred in 3 of the 10 study subjects. The prophylactic PFA regimen was thus safe and it may reduce the risk of limbic encephalitis, but is not considered to be potent enough to prevent HHV-6 reactivation. (C) 2011 John Wiley & Sons A/S
Individual hematopoietic stem cells in human bone marrow of patients with aplastic anemia or myelodysplastic syndrome stably give rise to limited cell lineages
Mutation of the phosphatidylinositol N-acetylglucosaminyltransferase subunit A (PIG-A) gene in hematopoietic stem cells (HSCs) results in the loss of glycosylphosphatidylinositol- anchored proteins (GPI-APs) on HSCs, but minimally affects their development, and thus can be used as a clonal maker of HSCs. We analyzed GPI-APs expression on six major lineage cells in a total of 574 patients with bone marrow (BM) failure in which microenvironment itself is thought to be unaffected, including aplastic anemia (AA) or myelodysplastic syndrome (MDS). GPI-APs-deficient (GPIAPs-) cells were detected in 250 patients. Whereas the GPIAPs- cells were seen in all six lineages in a majority of patients who had higher proportion ([dbmtequ]3%) of GPIAPs- cells, they were detected in only limited lineages in 92.9% of cases in the lower proportion (<3%) group. In all 250 cases, the same lineages of GPI-APs- cells were detected even after 6-18-month intervals, indicating that the GPIAPs- cells reflect hematopoiesis maintained by a self-renewing HSC in most of cases. The frequency of clones with limited lineages seen in mild cases of AA was similar to that in severe cases, and clones with limited lineages were seen even in two health volunteer cases. These results strongly suggest most individual HSCs produce only restricted lineages even in a steady state. While this restriction could reflect heterogeneity in the developmental potential of HSCs, we propose an alternative model in which the BM microenvironment is mosaic in supporting commitment of progenitors toward distinct lineages. Our computer simulation based on this model successfully recapitulated the observed clinical data. © AlphaMed Press
Increased glycosylphosphatidylinositol-anchored protein-deficient granulocytes define a benign subset of bone marrow failures in patients with trisomy 8
Trisomy 8 (+8), one of the most common chromosomal abnormalities found in patients with myelodysplastic syndromes (MDS), is occasionally seen in patients with otherwise typical aplastic anemia (AA). Although some studies have indicated that the presence of +8 is associated with the immune pathophysiology of bone marrow (BM) failure, its pathophysiology may be heterogeneous. We studied 53 patients (22 with AA and 31 with low-risk MDS) with +8 for the presence of increased glycosylphosphatidylinositol-anchored protein-deficient (GPI-AP-) cells, their response to immunosuppressive therapy (IST), and their prognosis. A significant increase in the percentage of GPI-AP- cells was found in 14 (26%) of the 53 patients. Of the 26 patients who received IST, including nine with increased GPI-AP- cells and 17 without increased GPI-AP- cells, 14 (88% with increased GPI-AP- cells and 41% without increased GPI-AP- cells) improved. The overall and event-free survival rates of the +8 patients with and without increased GPI-AP- cells at 5 yr were 100% and 100% and 59% and 57%, respectively. Examining the peripheral blood for the presence of increased GPI-AP- cells may thus be helpful for choosing the optimal treatment for +8 patients with AA or low-risk MDS. © 2014 John Wiley & Sons A/S
Mismatch of minor histocompatibility antigen contributes to a graft-versus-leukemia effect rather than to acute GVHD, resulting in long-term survival after HLA-identical stem cell transplantation in Japan
金沢大学大学院医学系研究科We determined the alleles of five polymorphic molecules including HA-1 and four adhesion molecules for 106 patients transplanted with HLA-identical stem cell grafts and investigated the association of mismatches as correlates of relapse and graft-versus-host disease (GVHD). All 106 recipients underwent stem cell transplantation (SCT) after myeloablative conditioning between 1985 and 2002. Risk status of disease at SCT was standard (n = 63) and high (n = 42). After SCT, 36, 49 and 33 developed acute GVHD, chronic GVHD and relapsed, respectively. Our patients relapsed at rates of 16.7 and 38.6% with one or more and without incompatibilities (P = 0.013). The relapse rates of patients with CD62L, CD31 codon 563, CD31 codon 125, HA-1 and CD49b incompatibilities were 5.9, 11.8, 15.4, 16.0 and 33.3%, respectively. The frequency of acute GVHD did not differ regardless of incompatibilities. In standard-risk group, the accumulated relapse rates of 19 and 44 patients with and without minor histocompatibility antigen incompatibility were 22% and unexpectedly 66%, respectively (P = 0.02). The probability of 12-year survival was 88% in the former and 66% in the latter patients (P = 0.03). Our data suggest that incompatibility of CD62L, CD31 codon 563 and CD31 codon 125 contributes to a graft-versus-leukemia effect rather than to GVHD, resulting in prolonged survival after HLA-identical SCT
Clinical significance and origin of leukocytes that lack HLA-A allele expression in patients with acquired aplastic anemia
To gain insight into the origin and clinical significance of leukocytes that lack human leukocyte antigen A (HLA-A) allele expression caused by a copy-number-neutral loss of heterozygosity in the short arm of chromosome 6 in patients with acquired aplastic anemia (AA), we used a high-sensitivity flow cytometry assay to investigate the presence of HLA-A allele-lacking leukocytes (HLA-LLs) in 144 AA patients. HLA-LLs, accounting for 0.2–99.8% of each leukocyte population, were detected in 18 of 71 (25.4%) newly diagnosed patients and in 25 of 73 (34.2%) previously treated patients. The lineage combination patterns of the HLA-LLs in the 43 HLA-LL+ patients were granulocytes (Gs), monocytes (Ms), B cells (Bs), and T cells (Ts; GMBT) in 13 cases, GMB in 16 cases, GM in 11 cases, and B alone in three cases. The response rate to antithymocyte globulin plus cyclosporine therapy (100%) and the 2-year, failure-free survival rate (100%) in 8 newly diagnosed HLA-LL+ patients were significantly higher than in 23 HLA-LL− patients (52.2% for both). These data suggest that HLA-LLs are a useful marker of the presence of immune pathophysiology in AA and that T-cell attacks against hematopoietic progenitor cells, rather than against hematopoietic stem cells, can trigger bone marrow failure in AA patients. © 2016 ISEH - International Society for Experimental HematologyEmbargo Period 12 month
Frequent loss of HLA alleles associated with copy number-neutral 6pLOH in acquired aplastic anemia
Idiopathic aplastic anemia (AA) is a common cause of acquired BM failure. Although autoimmunity to hematopoietic progenitors is thought to be responsible for its pathogenesis, little is known about the molecular basis of this autoimmunity. Here we show that a substantial proportion of AA patients harbor clonal hematopoiesis characterized by the presence of acquired copy number-neutral loss of heterozygosity (CNN-LOH) of the 6p arms (6pLOH). The 6pLOH commonly involved the HLA locus, leading to loss of one HLA haplotype. Loss of HLA-Aexpression from multiple lineages of leukocytes was confirmed by flow cytometry in all 6pLOH(+) cases. Surprisingly, the missing HLAalleles in 6pLOH(+) clones were conspicuously biased to particular alleles, including HLA-A*02:01, A*02:06, A*31:01, and B*40:02. A large-scale epidemiologic study on the HLA alleles of patients with various hematologic diseases revealed that the 4 HLA alleles were over-represented in the germline of AA patients. These findings indicate that the 6pLOH(+) hematopoiesis found in AA represents "escapes"hematopoiesis from the autoimmunity, which is mediated by cytotoxic T cells that target the relevant autoantigens presented on hematopoietic progenitors through these class I HLAs. Our results provide a novel insight into the genetic basis of the pathogenesis of AA. © 2011 by The American Society of Hematology