302 research outputs found
Characteristics of polyamine stimulation of cyclic nucleotide-independent protein kinase reactions
Effects of polyamines on prostatic chromatin- and non-histone-protein-associated protein kinase reactions
Specific inhibition of the enzymic decarboxylation of S-adenosylmethionine by methylglyoxal bis(guanylhydrazone) and related substances
Lattice Calculation of the Strangeness Magnetic Moment of the Nucleon
We report on a lattice QCD calculation of the strangeness magnetic moment of
the nucleon. Our result is . The sea contributions
from the u and d quarks are about 80% larger. However, they cancel to a large
extent due to their electric charges, resulting in a smaller net sea
contribution of to the nucleon magnetic moment. As
far as the neutron to proton magnetic moment ratio is concerned, this sea
contribution tends to cancel out the cloud-quark effect from the Z-graphs and
result in a ratio of which is close to the SU(6) relation and
the experiment. The strangeness Sachs electric mean-square radius
is found to be small and negative and the total sea contributes substantially
to the neutron electric form factor.Comment: 10 pages, 5 figures, LaTex, UK/97-23, ADP-97-55/T28
Intramural esophagic hematoma secondary to coumarinic anticoagulation: a case report
Esophagic Intramural Hematoma is an uncommon clinical condition, with a prognosis which is essentially benign. On most cases, a predisposing or precipitating factor may be seen, with the most common ones being the history of esophagic instrumentation, food impactations and thrombocytopenia. In the following manuscript, the authors present the case of a 54-years-old male with history of valve replacement surgery, who was treated at the Clinica Cardiovascular (Medellin, Colombia), with a clinical case of Intramural Esophagic Hematoma that was later confirmed to be due to a Coumarinic overanticoagulation. On this case, it is evidenced that Intramural Esophagic Hematoma is an unrecognized complication of Courmarinic anticoagulation therapy
ACS imaging of star clusters in M51. I. Identification and radius distribution
We use HST/ACS observations of the spiral galaxy M51 in F435W, F555W and
F814W to select a large sample of star clusters with accurate effective radius
measurements in an area covering the complete disc of M51. We present the
dataset and study the radius distribution and relations between radius, colour,
arm/interarm region, galactocentric distance, mass and age. We select a sample
of 7698 (F435W), 6846 (F555W) and 5024 (F814W) slightly resolved clusters and
derive their effective radii by fitting the spatial profiles with analytical
models convolved with the point spread function. The radii of 1284 clusters are
studied in detail. We find cluster radii between 0.5 and ~10 pc, and one
exceptionally large cluster candidate with a radius of 21.6 pc. The median
radius is 2.1 pc. We find 70 clusters in our sample which have colours
consistent with being old GC candidates and we find 6 new "faint fuzzy"
clusters in, or projected onto, the disc of M51. The radius distribution can
not be fitted with a power law, but a log-normal distribution provides a
reasonable fit to the data. This indicates that shortly after the formation of
the clusters from a fractal gas, their radii have changed in a non-uniform way.
We find an increase in radius with colour as well as a higher fraction of
redder clusters in the interarm regions, suggesting that clusters in spiral
arms are more compact. We find a correlation between radius and galactocentric
distance which is considerably weaker than the observed correlation for old
Milky Way GCs. We find weak relations between cluster luminosity and radius,
but we do not observe a correlation between cluster mass and radius.Comment: 17 pages, 23 figures. Accepted for publication in A&
Inelastic production in polarized photon-hadron collisions
Presented here is a calculation of inelastic production in polarized
photon-hadron collisions under the framework of NRQCD factorization formalism.
We consider the photoproduction of \jpsi in the energy range relevant to
HERA. The Weizs\"acker-Williams approximation is adopted in the evaluation of
the cross sections for collisions. We found that this process can give
another independent test for the color-octet mechanism, and the different
features for the two color-octet processes may provide further informations on
the mechanism for inelastic \jpsi photoproduction. And the discrepancy on the
production asymmetry between various sets of polarized gluon distribution
functions is also found to be distinctive.Comment: 14pages, 6 PS figure
Finding benchmark brown dwarfs to probe the IMF as a function of time
Using a simulated disk brown dwarf (BD) population, we find that new large
area infrared surveys are expected to identify enough BDs covering wide enough
mass--age ranges to potentially measure the mass function down to ~0.03Mo, and
the BD formation history out to 10 Gyr, at a level capable of establishing if
BD formation follows star formation. We suggest these capabilities are best
realised by spectroscopic calibration of BD properties (Teff, g and [M/H])
which, when combined with a measured luminosity and an evolutionary model can
give BD mass and age relatively independent of BD atmosphere models. Such
calibration requires an empirical understanding of how BD spectra are affected
by variations in these properties, and thus the identification and study of
"benchmark BDs" whose age and composition can be established independently. We
identify the best sources of benchmark BDs as young open cluster members,
moving group members, and wide (>1000AU) BD companions to both subgiant stars
and high mass white dwarfs (WDs). We have used 2MASS to measure a wide L dwarf
companion fraction of 2.7(+0.7/-0.5)%, which equates to a BD companion fraction
of 34(+9/-6)% for an alpha~1 companion mass function. Using this value we
simulate populations of wide BD binaries, and estimate that 80(+21/-14)
subgiant--BD binaries, and 50(+13/-10) benchmark WD--BD binaries could be
identified using current and new facilities. The WD--BD binaries should all be
identifiable using the Large Area Survey component of UKIDSS combined with
Sloan. Discovery of the subgiant--BD binaries will require a NIR imaging
campaign around a large (~900) sample of Hipparcos subgiants. If identified,
spectral studies of these benchmark brown dwarfs could reveal the spectral
sensitivities across the Teff, g and [M/H] space probed by new surveys.Comment: 18 pages, 12 figures, accepted for publication in MNRA
Prostate transglutaminase (TGase-4) antagonizes the anti-tumour action of MDA-7/IL-24 in prostate cancer
Background
Transglutamiase-4 (TGase-4), also known as prostate transglutaminase, belongs to the TGase family and is uniquely expressed in the prostate gland. The functions of this interesting protein are not clearly defined. In the present study, we have investigated an unexpected link between TGase-4 and the melanoma differentiation-associated gene-7/interleukin-24 (MDA-7/IL-24), a cytokine known to regulate the growth and apoptosis of certain cancer and immune cells.
Methods
Frozen sections of normal and malignant human prostate tissues and human prostate cancer (PCa) cell lines PC-3 and CA-HPV-10, cell lines expressing low and high levels of TGase-4, and recombinant MDA-7/IL-24 (rhMDA-7/IL-24) were used. Expression construct for human TGase-4 was generated using a mammalian expression vector with full length human TGase-4 isolated from normal human prostate tissues. PC-3 cells were transfected with expression construct or control plasmid. Stably transfected cells for control transfection and TGase-4 over expression were created. Similarly, expression of TGase-4 in CA-HPV-10 cells were knocked down by way of ribozyme transgenes. Single and double immunofluorescence microscopy was used for localization and co-localization of TGase-4 and MDA-7/IL-24 in PCa tissues and cells with antibodies to TGase-4; MDA-7/IL-24; IL-20alpha; IL-20beta and IL-22R. Cell-matrix adhesion, attachment and migration were by electric cell substrate impedance sensing and growth by in vitro cell growth assay. A panel of small molecule inhibitors, including Akt, was used to determine signal pathways involving TGase-4 and MDA-7/IL-24.
Results
We initially noted that MDA-7 resulted in inhibition of cell adhesion, growth and migration of human PCa PC-3 cells which did not express TGase-4. However, after the cells over-expressed TGase-4 by way of transfection, the TGase-4 expressing cells lost their adhesion, growth and migratory inhibitory response to MDA-7. On the other hand, CA-HPV-10 cells, a cell type naturally expressing high levels of TGase-4, had a contrasting response to MDA-7 when compared with PC-3 cells. Inhibitor to Akt reversed the inhibitory effect of MDA-7, only in PC-3 control cells, but not the TGase-4 expressing PC-3 cells. In human prostate tissues, TGase-4 was found to have a good degree of co-localization with one of the MDA-7 receptor complexes, IL-20Ra.
Conclusion
The presence of TGase-4 has a biological impact on a prostate cancer cell's response to MDA-7. TGase-4, via mechanism(s) yet to be identified, blocked the action of MDA-7 in prostate cancer cells. This has an important implication when considering the use of MDA-7 as a potential anticancer cytokine in prostate cancer therapies
Oxymetholone promotes weight gain in patients with advanced human immunodeficiency virus (HIV-1) infection
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