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Notch1 mutations are found in more than 50% of human T cell acute lymphoblastic leukemia (T-ALL) cells. However, the functions of Notch1 for human T cell development and leukemogenesis are not well understood. To examine the role of Notch1, human hematopoietic stem cells (HSCs), which had been transduced with a constitutively active form of Notch1 (ICN1), were transplanted into severely immunodeficient NOD/Shi-scid-IL2rγ(null) (NOG) mice. We found that the great majority of the ICN1-expressing hematopoietic cells in the bone marrow expressed surface markers for T cells, such as CD3, CD4, and CD8, and that this T cell development was independent of the thymus. Accordingly, phenotypically mature CD8(+) single positive (SP) T cells were observed in the spleen. Furthermore, T-ALL developed in one NOG recipient mouse out of 26 that had been secondary transferred with the T cells developed in the first NOG mice. These results indicate that Notch1 signaling in HSCs promotes CD8(+) SP T cell development, and that T cell leukemogenesis may require additional oncogenic factors other than Notch1 activation.

In this paper we propose a data processing model called PIM towards management of personal information. This model is essentially based on a semantic data model AIS, and we define two sets of data manipulation languages, one is for visual operations, another for logic-based operations. Visual languages allow users to construct database queries utilizing iconic pictures over database diagrams while logic-based languages provide declarative semantics. The main result of this paper is that these two languages have the equivalent expressive power, that is to say, our visual language is complete. This means that the proposed visual language can be characterized by a logical framework.

A pitch is disclosed which is used as a raw material for making carbon fibers. The pitch has a quinoline insoluble content of 7-18% by weight and a toluene insoluble content of 70-90% by weight. Further, the pitch preferably has a n-heptane soluble content of 1.0% by weight or less. A process for producing the pitch is also disclosed. The process comprises carrying out thermal modification of a petroleum heavy residual oil having a boiling point of 400° C. or more (atmospheric pressure) and a sulfur content of 1.5% by weight or less. Insoluble substances are then separated and removed by heating at a temperature of 380° C. or less. Thereafter, a low boiling point fraction is removed by vacuum distillation. The pitch can be utilized to producd carbon fibers without breaking of filaments in spinning or adhesion by fusion of the fibers in infusibilization. The carbon fibers produced have a high tensile strength and high modulus of elasticity.