22 research outputs found

    Ni@onion-like carbon and Co@amorphous carbon: control of carbon structures by metal ion species in MOFs

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    We first report the facile synthesis of metal-carbon composites consisting of metal nanoparticles (NPs) and different types of carbon species: onion-like and amorphous carbon, Ni@onion-like carbon and Co@amorphous carbon. By simply changing the metal species in an isostructural metal-organic framework, thermal decompositions of MOF-74 directly afforded different types of metal NPs and carbon composites, which exhibited good electrical conductivity. In particular, the Ni@onion-like carbon, having a well-ordered carbon structure, had high electrical conductivity (sigma = 5.3 omega(-1) cm(-1) at 295 K), explained by a modified model of the Efros-Shklovskii variable range hopping

    Clinical significance and origin of leukocytes that lack HLA-A allele expression in patients with acquired aplastic anemia

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    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

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    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

    A rare case of concomitant huge exophytic gastrointestinal stromal tumor of the stomach and Kasabach-Merritt phenomenon

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    <p>Abstract</p> <p>Background</p> <p>We report an extremely rare case of concomitant huge exophytic GIST of the stomach and Kasabach-Merritt phenomenon (KMP).</p> <p>Case presentation</p> <p>The patient was a 67-year-old man experiencing abdominal distension since September 2006. A physical examination revealed a 25 × 30 cm hard mass that was palpable in the middle and lower left abdomen minimal intrinsic mobility and massive ascites. Since the admitted patient was diagnosed with DIC, surgery could not be performed. The patient received a platelet transfusion and the DIC was treated. Due to this treatment, the platelet count recovered to 7.0 × 10<sup>4</sup>; tumor resection was performed at 16 days after admission. Laparotomy revealed a huge extraluminal tumor arising from the greater curvature of the stomach that measured 25 × 30 cm and had not ruptured into the peritoneal cavity or infiltrated other organs. Partial gastric resection was performed. The resected mass measured 25 × 25 × 20 cm. In cross section, the tumor appeared hard and homogenous with a small polycystic area. Histopathology of the resected specimen showed large spindle cell GIST with >5/50 HPF (high-power field) mitotic activity. The postoperative course was uneventful, and the coagulopathy improved rapidly.</p> <p>Conclusion</p> <p>Since the characteristic of tumor in this case was hypervascularity with bleeding and necrotic lesions, coagulopathy was thought to be caused by the trapping of platelets within a large vasculized tumor mass.</p

    MOB1-YAP1/TAZ-NKX2.1 axis controls bronchioalveolar cell differentiation, adhesion and tumour formation

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    Mps One Binder Kinase Activator (MOB)1A/1B are core components of the Hippo pathway. These proteins, which coactivate LArge Tumour Suppressor homologue kinases, are also tumour suppressors. To investigate MOB1A/B’s roles in normal physiology and lung cancer, we generated doxycycline (Dox)-inducible, bronchioalveolar epithelium-specific, null mutations of MOB1A/B in mice (SPC-rtTA/(tetO)7-Cre/Mob1aflox/flox/Mob1b−/−; termed luMob1DKO mice). Most mutants (70%) receiving Dox in utero (luMob1DKO (E6.5-18.5) mice) died of hypoxia within 1 h post-birth. Their alveolar epithelial cells showed increased proliferation, impaired YAP1/TAZ-dependent differentiation and decreased surfactant protein production, all features characteristic of human respiratory distress syndrome. Intriguingly, mutant mice that received Dox postnatally (luMob1DKO (P21–41) mice) did not develop spontaneous lung adenocarcinomas, and urethane treatment-induced lung tumour formation was decreased (rather than increased). Lungs of luMob1DKO (P21–41) mice exhibited increased detachment of bronchiolar epithelial cells and decreased numbers of the bronchioalveolar stem cells thought to initiate lung adenocarcinomas. YAP1/TAZ-NKX2.1-dependent expression of collagen XVII, a key hemidesmosome component, was also reduced. Thus, a MOB1-YAP1/TAZ-NKX2.1 axis is essential for normal lung homeostasis and expression of the collagen XVII protein necessary for alveolar stem cell maintenance in the lung niche
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