441 research outputs found
Survivin a radiogenetic promoter for glioblastoma viral gene therapy independently from CArG motifs
BACKGROUND: Radiogenetic therapy is a novel approach in the treatment of cancer, which employs genetic modification to alter the sensitivity of tumor cells to the effect of applied radiation. AIM: To select a potent radiation inducible promoter in the context of brain tumors and to investigate if CArG radio responsive motifs or other elements in the promoter nucleotide sequences can correlate to its response to radiation. METHODS: To select initial candidates for promoter inducible elements, the levels of mRNA expression of six different promoters were assessed using Quantitative RTPCR in D54 MG cells before and after radiation exposure. Recombinant Ad/reporter genes driven by five different promoters; CMV, VEGF, FLT-1, DR5 and survivin were constructed. Glioma cell lines were infected with different multiplicity of infection of the (promoter) Ad or CMV Ad. Cells were then exposed to a range of radiation (0â12Â Gy) at single fraction. Fluorescent microscopy, Luc assay and X-gal staining was used to detect the level of expression of related genes. Different glioma cell lines and normal astrocytes were infected with Ad survivin and exposed to radiation. The promoters were analyzed for presence of CArG radio-responsive motifs and CCAAT box consensus using NCBI blast bioinformatics software. RESULTS: Radiotherapy increases the expression of gene expression by 1.25â2.5 fold in different promoters other than survivin after 2Â h of radiation. RNA analysis was done and has shown an increase in copy number of tenfold for survivin. Most importantly cells treated with RT and Ad Luc driven by survivin promoter showed a fivefold increase in expression after 2Â Gy of radiation in comparison to non-irradiated cells. Presence or absence of CArG motifs did not correlate with promoter response to radiation. Survivin with the best response to radiation had the lowest number of CCAAT box. CONCLUSION: Survivin is a selective potent radiation inducible promoter for glioblastoma viral gene therapy and this response to radiation could be independent of CArG motifs
H Emission Nebulosity Associated with KH 15D
An H emission filament is found in close proximity to the unique object
KH 15D using the adaptive optics system of the Subaru Telescope. The morphology
of the filament, the presence of spectroscopic outflow signatures observed by
Hamilton et al., and the detection of extended H emission from KH 15D by
Deming, Charbonneau, & Harrington suggest that this filament arises from
shocked H in an outflow. The filament extends about 15" to the north of KH
15D.Comment: 11 pages, 3 figures, 1 table. Astrophysical Journal Letters, in pres
Near-Infrared Adaptive Optics Spectroscopy of Binary Brown Dwarf HD 130948B and C
We present near-infrared spectroscopy of low-mass companions in a nearby
triple system HD 130948 (Gliese 564, HR 5534). Adaptive optics on the Subaru
Telescope allowed spectroscopy of the individual components of the 0".13 binary
system. Based on a direct comparison with a series of template spectra, we
determined the spectral types of HD 130948B and C to be L4 +- 1. If we take the
young age of the primary star into account (0.3-0.8 Gyr), HD 130948B and C most
likely are a binary brown dwarf system.Comment: 6 pages, 3 figures, accepted for publication in ApJ Letter
A Subarcsecond Companion to the T Tauri Star AS 353B
Adaptive optics imaging of the bright visual T Tauri binary AS 353 with the
Subaru Telescope shows that it is a hierarchical triple system. The secondary
component, located 5.6" south of AS 353A, is resolved into a subarcsecond
binary, AS 353Ba and Bb, separated by 0.24". Resolved spectroscopy of the two
close components shows that both have nearly identical spectral types of about
M1.5. Whereas AS 353A and Ba show clear evidence for an infrared excess, AS
353Bb does not. We discuss the possible role of multiplicity in launching the
large Herbig-Haro flow associated with AS 353A.Comment: AASTeXv5.0, 21 pages, 5 figures, Astronomical Journal, in pres
An Instruction on the In Vivo Shell-Less Chorioallantoic Membrane 3-Dimensional Tumor Spheroid Model
The traditional shell chicken chorioallantoic membrane (CAM) model has been used extensively in cancer research to study tumor growth and angiogenesis. Here we present a combined in vivo tumor spheroid and shell-less CAM three-dimensional model for use in quantitative and qualitative analysis. With this model, the angiogenic and tumorigenic environments can be generated locally without exogenous growth factors. This physiological model offers a stable, static and flat environment that features a large working area and wider field of view useful for imaging and biomedical engineering applications. The short experimental time frame allows for rapid data acquisition, screening and validation of biomedical devices. The method and application of this shell-less model are discussed in detail, providing a useful tool for biomedical engineering research
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