3,402 research outputs found
1,25-Dihydroxyvitamin D3-induced differentiation in a human promyelocytic leukemia cell line (HL-60): receptor-mediated maturation to macrophage-like cells.
The human-derived promyelocytic leukemia cell line, HL-60, is known to differentiate into mature myeloid cells in the presence of 1,25-dihydroxyvitamin D3 (1,25[OH]2D3). We investigated differentiation by monitoring 1,25(OH)2D3-exposed HL-60 cells for phagocytic activity, ability to reduce nitroblue tetrazolium, binding of the chemotaxin N-formyl-methionyl-leucyl-[3H]phenylalanine, development of nonspecific acid esterase activity, and morphological maturation of Wright-Giemsa-stained cells. 1,25(OH)2D3 concentrations as low as 10(-10) M caused significant development of phagocytosis, nitroblue tetrazolium reduction, and the emergence of differentiated myeloid cells that had morphological characteristics of both metamyelocytes and monocytes. These cells were conclusively identified as monocytes/macrophages based upon their adherence to the plastic flasks and their content of the macrophage-characteristic nonspecific acid esterase enzyme. The estimated ED50 for 1,25(OH)2D3-induced differentiation based upon nitroblue tetrazolium reduction and N-formyl-methionyl-leucyl-[3H]phenylalanine binding was 5.7 X 10(-9) M. HL-60 cells exhibited a complex growth response with various levels of 1,25(OH)2D3: less than or equal to 10(-10) M had no detectable effect, 10(-9) M stimulated growth, and greater than or equal to 10(-8) M sharply inhibited proliferation. We also detected and quantitated the specific receptor for 1,25(OH)2D3 in HL-60 and HL-60 Blast, a sub-clone resistant to the growth and differentiation effects of 1,25(OH)2D3. The receptor in both lines was characterized as a DNA-binding protein that migrated at 3.3S on high-salt sucrose gradients. Unequivocal identification was provided by selective dissociation of the 1,25(OH)2D3-receptor complex with the mercurial reagent, p-chloromercuribenzenesulfonic acid, and by a shift in its sedimentation position upon complexing with anti-receptor monoclonal antibody. On the basis of labeling of whole cells with 1,25(OH)2[3H]D3 in culture, we found that HL-60 contains approximately 4,000 1,25(OH)2D3 receptor molecules per cell, while the nonresponsive HL-60 Blast is endowed with approximately 8% of that number. The concentration of 1,25(OH)2D3 (5 X 10(-9) M) in complete culture medium, which facilitates the saturation of receptors in HL-60 cells, is virtually identical to the ED50 for the sterol's induction of differentiation. This correspondence, plus the resistance of the relatively receptor-poor HL-60 Blast, indicates that 1,25(OH)2D3-induced differentiation of HL-60 cells to monocytes/macrophages is occurring via receptor-mediated events
Parton recombination and fluctuations of conserved charges
We study various fluctuation and correlation signals of the deconfined state using a dynamical recombination approach (quark Molecular Dynamics, qMD). We analyse charge ratio fluctuations, charge transfer fluctuations and baryon-strangeness correlations as a function of the center of mass energy with a set of central Pb+Pb/Au+Au events from AGS energies on (Elab = 4 AGeV) up to the highest RHIC energy available (V sNN = 200 GeV) and as a function of time with a set of central Au+Au qMD events at V sNN = 200 GeV with and without applying our hadronization procedure. For all studied quantities, the results start from values compatible with a weakly coupled QGP in the early stage and end with values compatible with the hadronic result in the final state. We show that the loss of the signal occurs at the same time as hadronization and trace it back to the dynamical recombination process implemented in our model
Canonical, Stable, General Mapping using Context Schemes
Motivation: Sequence mapping is the cornerstone of modern genomics. However,
most existing sequence mapping algorithms are insufficiently general.
Results: We introduce context schemes: a method that allows the unambiguous
recognition of a reference base in a query sequence by testing the query for
substrings from an algorithmically defined set. Context schemes only map when
there is a unique best mapping, and define this criterion uniformly for all
reference bases. Mappings under context schemes can also be made stable, so
that extension of the query string (e.g. by increasing read length) will not
alter the mapping of previously mapped positions. Context schemes are general
in several senses. They natively support the detection of arbitrary complex,
novel rearrangements relative to the reference. They can scale over orders of
magnitude in query sequence length. Finally, they are trivially extensible to
more complex reference structures, such as graphs, that incorporate additional
variation. We demonstrate empirically the existence of high performance context
schemes, and present efficient context scheme mapping algorithms.
Availability and Implementation: The software test framework created for this
work is available from
https://registry.hub.docker.com/u/adamnovak/sequence-graphs/.
Contact: [email protected]
Supplementary Information: Six supplementary figures and one supplementary
section are available with the online version of this article.Comment: Submission for Bioinformatic
Event-by-Event Analysis of Baryon-Strangeness Correlations: Pinning Down the Critical Temperature and Volume of QGP Formation
The recently proposed baryon-strangeness correlation (C_BS) is studied with a
string-hadronic transport model (UrQMD) for various energies from E_lab=4 AGeV
to \sqrt s=200 AGeV. It is shown that rescattering among secondaries can not
mimic the predicted correlation pattern expected for a Quark-Gluon-Plasma.
However, we find a strong increase of the C_BS correlation function with
decreasing collision energy both for pp and Au+Au/Pb+Pb reactions. For Au+Au
reactions at the top RHIC energy (\sqrt s=200 AGeV), the C_BS correlation is
constant for all centralities and compatible with the pp result. With
increasing width of the rapidity window, C_BS follows roughly the shape of the
baryon rapidity distribution. We suggest to study the energy and centrality
dependence of C_BS which allow to gain information on the onset of the
deconfinement transition in temperature and volume
Saturn sa-9/pegasus a postflight trajectory
Postflight trajectory analysis and orbital flight discussion for Saturn I /SA- 9/ launch vehicle carrying Pegasus payloa
Identifying Novel Epigenetic Dependencies in Pre-Leukemic Hematopoietic Stem Cells
From the Washington University Office of Undergraduate Research Digest (WUURD), Vol. 13, 05-01-2018. Published by the Office of Undergraduate Research. Joy Zalis Kiefer, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Lindsey Paunovich, Editor; Helen Human, Programs Manager and Assistant Dean in the College of Arts and Sciences Mentor(s): Grant Challe
Exegesis on Done Not Finished
The creation of Done Not Finished is part of practice-led research on the concept of time through the method of dance-making. Dance-making can be thought of as performative research in the sense that it is expressed in non-numerical data. Instead it encompasses material forms of practice, music and sound, space and time, and takes into account both the perspectives of the researcher and collaborative inquiry. This piece evolved over a year\u27s time- going through multiple casts, performance settings and audiences, and various stakeholders. While the last performance was cancelled, this piece emphasizes the importance of process over product
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