36 research outputs found

    Fischer–Tropsch Synthesis Over Zr-Promoted Co/γ-Al2O3 Catalysts

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    Two Zr-modified alumina supports were synthetized containing the same amount of Zr but a different distribution of this modifier over the alumina surface. These supports, together with the unmodified alumina carrier, were used to prepare three cobalt-based catalysts which were characterized and tested under relevant Fischer–Tropsch conditions. The three catalysts presented very similar porosity and cobalt dispersion. The addition of Zr nor its distribution enhanced the catalyst reducibility. The catalyst activity was superior when using a carrier consisting of large ZrO2 islands over the alumina surface. The use of a carrier with a homogeneous Zr distribution had however, a detrimental effect. Moreover, a faster initial deactivation rate was observed for the Zr-promoted catalysts, fact that may explain this contradictory effect of Zr on activity. Finally, the addition of Zr showed a clear enhancement of the selectivity to long chain hydrocarbons and ethylene, especially when Zr was well dispersed

    Integrated acoustic immunoaffinity-capture (IAI) platform for detection of PSA from whole blood samples.

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    On-chip detection of low abundant protein biomarkers is of interest to enable point-of-care diagnostics. Using a simple form of integration, we have realized an integrated microfluidic platform for the detection of prostate specific antigen (PSA), directly in anti-coagulated whole blood. We combine acoustophoresis-based separation of plasma from undiluted whole blood with a miniaturized immunoassay system in a polymer manifold, demonstrating improved assay speed on our Integrated Acoustic Immunoaffinity-capture (IAI) platform. The IAI platform separates plasma from undiluted whole blood by means of acoustophoresis and provides cell free plasma of clinical quality at a rate of 10 uL/min for an online immunoaffinity-capture of PSA on a porous silicon antibody microarray. The whole blood input (hematocrit 38-40%) rate was 50 μl min(-1) giving a plasma volume fraction yield of ≈33%. PSA was immunoaffinity-captured directly from spiked female whole blood samples at clinically significant levels of 1.7-100 ng ml(-1) within 15 min and was subsequently detected via fluorescence readout, showing a linear response over the entire range with a coefficient of variation of 13%

    SOCS2 is dispensable for BCR/ABL1-induced chronic myeloid leukemia-like disease and for normal hematopoietic stem cell function

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    Suppressor of cytokine signaling 2 (SOCS2) is known as a feedback inhibitor of cytokine signaling and is highly expressed in primary bone marrow (BM) cells from patients with chronic myeloid leukemia (CML). However, it has not been established whether SOCS2 is involved in CML, caused by the BCR/ABL1 fusion gene, or important for normal hematopoietic stem cell (HSC) function. In this study, we demonstrate that although Socs2 was found to be preferentially expressed in long-term HSCs, Socs2-deficient HSCs were indistinguishable from wild-type HSCs when challenged in competitive BM transplantation experiments. Furthermore, by using a retroviral BCR/ABL1-induced mouse model of CML, we demonstrate that SOCS2 is dispensable for the induction and propagation of the disease, suggesting that the SOCS2-mediated feedback regulation of the JAK/STAT pathway is deficient in BCR/ABL1-induced CML.N Hansen, H Ågerstam, M Wahlestedt, N Landberg, M Askmyr, M Ehinger, M Rissler, H Lilljebjörn, P Johnels, J Ishiko, J V Melo, W S Alexander, D Bryder, M Järås, and T Fioreto

    Arrayed molecular barcoding of leukemic stem cells

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    Functional screens on cancer cells using compound or protein libraries are usually performed in vitro. However, to assess the effects on leukemia stem cells (LSCs) in a screening setting, methodologies that allow for a high-throughput in vivo readout of leukemia-initiating activity are needed. One experimental approach to solve this issue is to genetically label, also referred to as “barcoding,” the leukemia cells in an arrayed format prior to exposing them to separate experimental conditions. The cells can then be pooled and injected into mice for competitive readout of leukemia-initiating activity. Here, we describe a procedure for combining lentiviral arrayed molecular barcoding of leukemia cells with next-generation sequencing, to enable screens on leukemia cells ex vivo followed by an in vivo competitive readout of LSC function. This methodology can also be applied to other model systems in which a competitive in vivo readout of cells is needed

    Interleukin 4 induces apoptosis of acute myeloid leukemia cells in a Stat6 dependent manner

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    Cytokines provide signals that regulate immature normal and acute myeloid leukemia (AML) cells in the bone marrow microenvironment. We here identify interleukin 4 (IL4) as a selective inhibitor of AML cell growth and survival in a cytokine screen using fluorescently labeled AML cells. RNA-sequencing of the AML cells revealed an IL4-induced upregulation of Stat6 target genes and enrichment of apoptosis-related gene expression signatures. Consistent with these findings, we found that IL4 stimulation of AML cells induced Stat6 phosphorylation and that disruption of Stat6 using CRISPR/Cas9-genetic engineering rendered cells partially resistant to IL4-induced apoptosis. To evaluate whether IL4 inhibits AML cells in vivo, we expressed IL4 ectopically in AML cells transplanted into mice and also injected IL4 into leukemic mice; both strategies resulted in the suppression of the leukemia cell burden and increased survival. Notably, IL4 exposure caused reduced growth and survival of primary AML CD34(+)CD38(-) patient cells from several genetic subtypes of AML, whereas normal stem and progenitor cells were less affected. The IL4-induced apoptosis of AML cells was linked to Caspase-3 activation. Our results demonstrate that IL4 selectively induces apoptosis of AML cells in a Stat6-dependent manner, findings that may translate into new therapeutic opportunities in AML.Leukemia accepted article preview online, 18 August 2017. doi:10.1038/leu.2017.261

    Sol-gel integrated protein microarray for high-resolution signal readout of psa (prostate specific antigen) in clinical samples

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    In this study, we demonstrate a new protein microarray technology for highly sensitive detection of PSA (prostate caser specific antigen) in scrum samples. Using the optically active sol-gel nanocomposites, which can hold capturing probes in native and surface morphology tailored porous silicon, purified PSA (Prostate Specific Antigen) in human female serum was assessed by FlTC-antiPSA in broad dynamic range of the sandwich (1 pg/mL to Ing/mL). Additionally, we tested reverse phase assay using our developed system, which purified PSA imbedded in sol-gel and FITC labeled its counter antibody was accessed. Dynamic range was 60 fg/mL to 6ng/mL. Our concept can allow the measurement oflow amount of PSA at pg/ml range and thus, it is possible to do relative quantification for marker protein as well

    In-depth genetic analysis of sclerosing epithelioid fibrosarcoma reveals recurrent genomic alterations and potential treatment targets

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    PURPOSE: Sclerosing epithelioid fibrosarcoma (SEF) is a highly aggressive soft tissue sarcoma closely related to low-grade fibromyxoid sarcoma (LGFMS). Some tumors display morphological characteristics of both SEF and LGFMS, so called hybrid SEF/LGFMS. Despite the overlap of gene fusion variants between these two tumor types, SEF is much more aggressive. The present study aimed to further characterize SEF and hybrid SEF/LGFMS genetically in order to better understand the role of the characteristic fusion genes and possible additional genetic alterations in tumorigenesis.EXPERIMENTAL DESIGN: We performed whole exome sequencing, single nucleotide polymorphism (SNP) array analysis, RNA-sequencing (RNA-seq), global gene expression analyses and/or IHC on a series of 13 SEFs and 6 hybrid SEF/LGFMS. We also expressed the FUS-CREB3L2 and EWSR1-CREB3L1 fusion genes conditionally in a fibroblast cell line; these cells were subsequently analyzed by RNA-seq and expression of the CD24 protein was assessed by FACS analysis.RESULTS: The SNP array analysis detected a large number of structural aberrations in SEF and SEF/LGFMS, many of which were recurrent, notably DMD microdeletions. RNA-seq identified FUS-CREM and PAX5-CREB3L1 as alternative fusion genes in one SEF each. CD24 was strongly upregulated, presumably a direct target of the fusion proteins. This was further confirmed by the gene expression analysis and FACS analysis on Tet-On 3G cells expressing EWSR1-CREB3L1.CONCLUSIONS: While gene fusions are the primary tumorigenic events in both SEF and LGFMS, additional genomic changes explain the differences in aggressiveness and clinical outcome between the two types. CD24 and DMD constitute potential therapeutic targets
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