Motoshi Ichikawa

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The Notch genes play a key role in cellular differentiation. The significance of Notch1 during thymocyte development is well characterized, but the function of Notch2 is poorly understood. Here we demonstrate that Notch2 but no other Notch family member is preferentially expressed in mature B cells and that conditionally targeted deletion of Notch2 results(More)
Embryonic development of multilineage hematopoiesis requires the precisely regulated expression of lineage-specific transcription factors, including AML-1 (encoded by Runx1; also known as CBFA-2 or PEBP-2alphaB). In vitro studies and findings in human diseases, including leukemias, myelodysplastic syndromes and familial platelet disorder with predisposition(More)
Evi-1 has been recognized as one of the dominant oncogenes associated with murine and human myeloid leukemia. Here, we show that hematopoietic stem cells (HSCs) in Evi-1-deficient embryos are severely reduced in number with defective proliferative and repopulating capacity. Selective ablation of Evi-1 in Tie2(+) cells mimics Evi-1 deficiency, suggesting(More)
Intrathymic development of CD4/CD8 double-negative (DN) thymocytes can be tracked by well-defined chronological subsets of thymocytes, and is an ideal target of gene expression profiling analysis to clarify the genetic basis of mature T cell production, by which differentiation of immature thymocytes is investigated in terms of gene expression profiles. In(More)
RATIONALE Identification of patients with drug-resistant pathogens at initial diagnosis is essential for treatment of pneumonia. OBJECTIVES To elucidate clinical features of community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP), and to clarify risk factors for drug-resistant pathogens in patients with CAP and HCAP. METHODS A(More)
The Notch1-RBP-Jkappa and the transcription factor Runx1 pathways have been independently shown to be indispensable for the establishment of definitive hematopoiesis. Importantly, expression of Runx1 is down-regulated in the para-aortic splanchnopleural (P-Sp) region of Notch1- and Rbpsuh-null mice. Here we demonstrate that Notch1 up-regulates Runx1(More)
The lymphocyte-specific Cas family protein Cas-L (Crk-associated substrate lymphocyte type) has been implicated to function in lymphocyte movement, mediated mainly by integrin signaling. However, its physiological role is poorly understood. In this study we analyzed the function of Cas-L in lymphocytes using gene-targeted mice. The mutant mice showed a(More)
Transcription factor AML1/Runx1, initially isolated from the t(8;21) chromosomal translocation in human leukemia, is essential for the development of multilineage hematopoiesis in mouse embryos. AML1 negatively regulates the number of immature hematopoietic cells in adult hematopoiesis, whereas it is required for megakaryocytic maturation and lymphocytic(More)
OBJECTIVE Systemic mastocytosis with associated clonal hematological non-mast cell lineage disease (SM-AHNMD) is a distinct entity that was defined by World Health Organization. Systemic mastocytosis with acute myeloid leukemia (AML) is frequently seen among SM-AHNMD. However, the pathogenesis or origin of neoplastic mast cells has not been fully elucidated(More)
Acute eosinophilic pneumonia (AEP) is an acute febrile illness with respiratory impairment, diffuse pulmonary infiltrates, and eosinophilia in bronchoalveolar lavage (BAL) fluid. We report an adult male who developed severe cough and dyspnea with slight fever on day 78 after allogeneic hematopoietic stem transplantation. The symptoms coexisted with skin and(More)