662 research outputs found
The Effects of Arginine Deficiency on Lymphoma Cells
When L5178Y and L1210 mouse lymphosarcoma cells were incubated with rat or beef liver arginase there was up to 100% cell destruction in 24 hours. This was reversed specifically with arginine and partially with arginino-succinic acid, citrulline and ornithine. The concentration of arginine was critical; at 8 μmol/l the cells remained viable and reversible inhibition could be shown; below this level cells died. L5178Y cells were grown in medium containing from 0 to 80 μmol/l arginine for 24 hours then transferred to fresh medium for 24 hours. Viable cell counts and mitotic indices were determined, and cells were pulsed with 3H-thymidine, 3H-uridine, 14C-leucine and 14C-arginine at various times. Thymidine uptake was affected most and preceded parallel changes in viable cell numbers. It was concluded that arginine is required by these cells even in a “resting” state and despite some evidence for their capacity to utilize precursors, the tumour cells underwent rapid and extensive destruction when available arginine was severely depleted
The location of U.S. sugarbeet production
Cover title.Includes bibliographical references (pages 193-207)
Shubnikov de Haas effect in the metallic state of NaCoO
Shubnikov de Haas oscillations for two well defined frequencies,
corresponding respectively to areas of 0.8 and 1.36% of the first Brillouin
zone (FBZ), were observed in single crystals of NaCoO. The
existence of Na superstructures in NaCoO, coupled with this
observation, suggests the possibility that the periods are due to the
reconstruction of the large Fermi surface around the point. An
alternative interpretation in terms of the long sought-after
pockets is also considered but found to be incompatible
with existing specific heat data.Comment: 5 pages 4 figure
Topical and Systemic Cannabidiol Improves Trinitrobenzene Sulfonic Acid Colitis in Mice
Background/Aims: Compounds of Cannabis sativa are known to exert anti-inflammatory properties, some of them without inducing psychotropic side effects. Cannabidiol (CBD) is such a side effect-free phytocannabinoid that improves chemically induced colitis in rodents when given intraperitoneally. Here, we tested the possibility whether rectal and oral application of CBD would also ameliorate colonic inflammation, as these routes of application may represent a more appropriate way for delivering drugs in human colitis. Methods: Colitis was induced in CD1 mice by trinitrobenzene sulfonic acid. Individual groups were either treated with CBD intraperitoneally (10 mg/kg), orally (20 mg/kg) or intrarectally (20 mg/kg). Colitis was evaluated by macroscopic scoring, histopathology and the myeloperoxidase (MPO) assay. Results: Intraperitoneal treatment of mice with CBD led to improvement of colonic inflammation. Intrarectal treatment with CBD also led to a significant improvement of disease parameters and to a decrease in MPO activity while oral treatment, using the same dose as per rectum, had no ameliorating effect on colitis. Conclusion: The data of this study indicate that in addition to intraperitoneal application, intrarectal delivery of cannabinoids may represent a useful therapeutic administration route for the treatment of colonic inflammation. Copyright (C) 2012 S. Karger AG, Base
Infrared Diagnostics for the Extended 12 micron Sample of Seyferts
We present an analysis of Spitzer IRS spectroscopy of 83 active galaxies from
the extended 12 micron sample. We find rank correlations between several
tracers of star formation which suggest that (1) the PAH feature is a reliable
tracer of star formation, (2) there is a significant contribution to the
heating of the cool dust by stars, (3) the H emission is also primarily
excited by star formation. The 55-90 vs. 20-30 spectral index plot is also a
diagnostic of the relative contribution of Starburst to AGN. We see there is a
large change in spectral index across the sample. Thus, the contribution to the
IR spectrum from the AGN and starburst components can be comparable in
magnitude but the relative contribution also varies widely across the sample.
We find rank correlations between several AGN tracers. We search for
correlations between AGN and Starburst tracers and we conclude that the AGN and
Starburst tracers are not correlated. This is consistent with our conclusion
that the relative strength of the AGN and Starburst components varies widely
across the sample. Thus, there is no simple link between AGN fueling and Black
Hole Growth and star formation in these galaxies. The distribution of Sil 10
micron and 18 micron strengths is consistent with the clumpy torus models of
Sirocky et al. We find a rank correlation between the [NeV] 14 micron line and
the 6.7 micron continuum which may be due to an extended component of hot dust.
The Sy 2s with a Hidden Broad Line Region (HBLR) have a higher ratio of AGN to
Starburst contribution to the SED than Sy 2s without an HBLR. This may
contribute to the detection of the HBLR in polarized light. The Sy 2s with an
HBLR are more similar to the Sy 1s than they are to the Sy 2s without an HBLR
A comparative study of adhesion of melanoma and breast cancer cells to blood and lymphatic endothelium
Background: Lymphovascular invasion (LVI) is an important step in the metastatic cascade; tumor cell migration
and adhesion to blood and lymphatic vessels is followed by invasion through the vessel wall and subsequent
systemic spread. Although primary breast cancers and melanomas have rich blood vascular networks, LVI is
predominately lymphatic in nature. Whilst the adhesion of tumor cells to blood endothelium has been extensively
investigated, there is a paucity of information on tumor cell adhesion to lymphatic endothelium.
Methods and Results: Breast cancer (MDA-MB-231 and MCF7) and melanoma (MeWo and SKMEL-30) cell
adhesion to lymphatic (hTERT-LEC and HMVEC dLy Neo) and blood (HUVEC and hMEC-1) endothelial cells
were assessed using static adhesion assays. The effect of inflammatory conditions, tumor necrosis factor-a
(TNF-a) stimulation of endothelial and tumor cells, on the adhesive process was also examined. In addition,
the effects of TNF-a stimulation on tumor cell migration was investigated using haplotaxis (scratch wound)
assays. Breast cancer and melanoma cells exhibited higher levels of adhesion to blood compared to lymphatic
endothelial cells ( p < 0.001). TNF-a stimulation of endothelial cells, or of tumor cells alone, did not significantly
alter tumor–endothelial cell adhesion or patterns.When both tumor and endothelial cells were stimulated with
TNF-a, a significant increase in adhesion was observed ( p < 0.01), which was notably higher in the lymphatic
cell models ( p < 0.001). TNF-a-stimulation of all tumor cell lines significantly increased their migration rate
( p < 0.01).
Conclusions: Results suggest that metastasis resultant from lymphatic vessel-tumor cell adhesion may be
modulated by cytokine stimulation, which could represent an important therapeutic target in breast cancer and
melanoma
HST/ACS Emission Line Imaging of Low Redshift 3CR Radio Galaxies I: The Data
We present 19 nearby (z<0.3) 3CR radio galaxies imaged at low- and
high-excitation as part of a Cycle 15 Hubble Space Telescope snapshot survey
with the Advanced Camera for Surveys. These images consist of exposures of the
H-alpha (6563 \AA, plus [NII] contamination) and [OIII] 5007 \AA emission lines
using narrow-band linear ramp filters adjusted according to the redshift of the
target. To facilitate continuum subtraction, a single-pointing 60 s line-free
exposure was taken with a medium-band filter appropriate for the target's
redshift. We discuss the steps taken to reduce these images independently of
the automated recalibration pipeline so as to use more recent ACS flat-field
data as well as to better reject cosmic rays. We describe the method used to
produce continuum-free (pure line-emission) images, and present these images
along with qualitative descriptions of the narrow-line region morphologies we
observe. We present H-alpha+[NII] and [OIII] line fluxes from aperture
photometry, finding the values to fall expectedly on the redshift-luminosity
trend from a past HST/WFPC2 emission line study of a larger, generally higher
redshift subset of the 3CR. We also find expected trends between emission line
luminosity and total radio power, as well as a positive correlation between the
size of the emission line region and redshift. We discuss the associated
interpretation of these results, and conclude with a summary of future work
enabled by this dataset.Comment: 18 pages, 12 figures, accepted for publication in ApJ
Magnetic field-dependent interplay between incoherent and Fermi liquid transport mechanisms in low-dimensional tau phase organic conductors
We present an electrical transport study of the 2-dimensional (2D) organic
conductor tau-(P-(S,S)-DMEDT-TTF)_2(AuBr)_2(AuBr_2)_y (y = 0.75) at low
temperatures and high magnetic fields. The inter-plane resistivity rho_zz
increases with decreasing temperature, with the exception of a slight anomaly
at 12 K. Under a magnetic field B, both rho_zz and the in-plane resistivity
plane rho_xx show a pronounced negative and hysteretic magnetoresistance with
Shubnikov de Haas (SdH)oscillations being observed in some (high
quality)samples above 15 T. Contrary to the predicted single, star-shaped,
closed orbit Fermi surface from band structure calculations (with an expected
approximate area of 12.5% of A_FBZ), two fundamental frequencies F_l and F_h
are detected in the SdH signal. These orbits correspond to 2.4% and 6.8% of the
area of the first Brillouin zone(A_FBZ), with effective masses F_l = 4.0 +/-
0.5 and F_h = 7.3 +/- 0.1. The angular dependence, in tilted magnetic fields of
F_l and F_h, reveals the 2D character of the FS and Angular dependent
magnetoresistance (AMRO) further suggests a FS which is strictly 2-D where the
inter-plane hopping t_c is virtually absent or incoherent. The Hall constant
R_xy is field independent, and the Hall mobility increases by a factor of 3
under moderate magnetic fields. Our observations suggest a unique physical
situation where a stable 2D Fermi liquid state in the molecular layers are
incoherently coupled along the least conducting direction. The magnetic field
not only reduces the inelastic scattering between the 2D metallic layers, but
it also reveals the incoherent nature of interplane transport in the AMRO
spectrum. The apparent ferromagnetism of the hysteretic magnetoresistance
remains an unsolved problem.Comment: 33 pages, 11 figure
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