980 research outputs found

    Targeted expression of human folylpolyglutamate synthase for selective enhancement of methotrexate chemotherapy in osteosarcoma cells

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    The antifolate methotrexate (MTX ) is an important chemotherapeutic agent for treatment of osteosarcoma. This drug is converted intracellularly into polyglutamate derivates by the enzyme folylpolyglutamate synthase (FPGS). MTX polyglutamates show an enhanced and prolonged cytotoxicity in comparison to the monoglutamate. In the present study, we proved the hypothesis that transfer of the human fpgs gene into osteosarcoma cells may augment their MTX sensitivity. For this purpose, we employed the human osteocalcin (OC) promoter, which had shown marked osteosarconna specificity in promoter studies using different luciferase assays in osteosarcoma and non-osteosarcoma cell lines. A recombinant lentiviral vector was generated with the OC promoter driving the expression of fpgs and the gene for enhanced green fluorescent protein (egfp), which was linked to fpgs by an internal ribosomal entry site (IRES). As the vector backbone contained only a self-inactivating viral LTR promoter, any interference of the OC promoter by unspecific promoter elements was excluded. We tested the expression of FPGS and enhanced green fluorescent protein (EGFP) after lentiviral transduction in various osteosarcoma cell lines (human MG-63 cells and TM 791 cells; rat osteosarconna (ROS) 17/2.8 cells) and non-osteogenic tumor cell lines (293T human embryonic kidney cells, He La human cervix carcinoma cells). EGFP expression and MTX sensitivity were assessed in comparison with non-transduced controls. Whereas the OC promoter failed to enhance MTX sensitivity via FPGS expression in non-osteogenic tumor cell lines, the OC promoter mediated a markedly increased MTX cytotoxicity in all osteosarcoma cell lines after lentiviral transduction. The present chemotherapy-enhancing gene therapy system may have great potential to overcome in future MTX resistance in human osteosarcomas.Elterninitiative Kinderkrebsklinik Dusseldorf e.V

    From Helmut Jürgensen’s former students: The game of informatics

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    Personal reflections are given on being students of Helmut Jürgensen. Then, we attempt to address his hypothesis that informatics follows trend-like behaviours through the use of a content analysis of university job advertisements, and then via simulation techniques from the area of quantitative economics

    Smalltalk Interpreter in Java

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    Author Helmut Rohregger, BSc.Kurzfassungen in deutscher und englischer SpracheMasterarbeit Universität Linz 201

    Smalltalk Interpreter in Java

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    Author Helmut Rohregger, BSc.Kurzfassungen in deutscher und englischer SpracheMasterarbeit Universität Linz 201

    HELMUT E. LUCK JAKO HISTORYK PSYCHOLOGII

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    The article presents the figure of Helmut E. Luck, well-known scientist in the world of historians of psychology. Helmut E. Luck also is well-known in Poland, as the author or the scientific editor of several books in the field of history of psychology. In the first part of the article the short presentation of his scientific career and his scientific achievements are demonstrated. The second part comprises the analysis of his opinions in the scope of social psychology. Helmut E. Luck was the one of pioneers in psychology, who paid attention to social positive phenomena or social positive behaviors. In the field of history of psychology, H.E.Luck made the contribution to methodological analysis of psychological ideas in history, preferring the model which underlines connection of psychology with culture and at the same time creates the opportunity to analysis of biographical plots. The article also shows unquestionable and unusually merits of Luck’s in popularization of knowledge about history of psychology.The article presents the figure of Helmut E. Luck, well-known scientist in the world of historians of psychology. Helmut E. Luck also is well-known in Poland, as the author or the scientific editor of several books in the field of history of psychology. In the first part of the article the short presentation of his scientific career and his scientific achievements are demonstrated. The second part comprises the analysis of his opinions in the scope of social psychology. Helmut E. Luck was the one of pioneers in psychology, who paid attention to social positive phenomena or social positive behaviors. In the field of history of psychology, H.E.Luck made the contribution to methodological analysis of psychological ideas in history, preferring the model which underlines connection of psychology with culture and at the same time creates the opportunity to analysis of biographical plots. The article also shows unquestionable and unusually merits of Luck’s in popularization of knowledge about history of psychology

    Die IPrA, Helmut und ich

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    This contribution describes the beginning and the development of the professional and personal relationship between Helmut and the author which has been highly influenced by our joint membership in the International Pragmatics Association and by our activities in and for the IPrA
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