115 research outputs found
Synergistic inhibitory effect of gemcitabine and angiotensin type-1 receptor blocker, losartan, on murine pancreatic tumor growth via anti-angiogenic activities.
Pancreatic cancer is one of the leading causes of cancer death, and represents a challenging chemotherapeutic problem. The crucial role of angiogenesis in tumor growth has been widely recognized, and several reports have revealed that the combination treatment of the conventional chemotherapeutic drugs and anti-angiogenic agents exerted synergistic anti-cancerous effects. It has been reported that the clinically used angiotensin type-1 receptor blocker (ARB) exerted potent anti-angiogenic activity. The aim of our current study was to examine the combination effect of gemcitabine (GEM), a widely used conventional chemotherapeutic drug against pancreas cancer, and losartan (Lo), an ARB, on murine pancreatic tumor growth, especially in conjunction with angiogenesis. When used individually, GEM and Lo at clinically comparable low doses moderately suppressed pancreatic tumor development. The combination treatment with GEM and Lo exerted a marked inhibitory effect as compared with single agent treatments even after the tumor was fully established. Neovascularization and the expression of the vascular endothelial growth factor (VEGF), a central angiogenic factor, in the tumor were both markedly suppressed in a magnitude similar to the inhibitory effects against the tumor growth. Since both agents are widely used in the clinical practice, the combination regimen of GEM and Lo may represent a potential new therapeutic strategy for pancreatic cancer in the future
Different tumoricidal effects of interferon subclasses and p53 status on hepatocellular carcinoma development and neovascularization.
Interferon (IFN) is known as a multifunctional cytokine. The aim of this study was to examine the different effects of IFN subclass; namely, IFN-α and IFN-β, on hepatocellular carcinoma (HCC) growth especially in conjunction with angiogenesis that is known to play a pivotal role in the tumor growth. Furthermore, we also examined whether the p53 status in the tumor would alter the anti-tumoral effect of IFN against HCC growth since the p53 status reportedly affected the therapeutic effect of anti-angiogenic agents against cancer. When compared with IFN-α, IFN-β exerted a more potent inhibitory effect on HCC growth, even after the tumor was established, along with suppression of neovascularization in the tumor. A single treatment with clinically comparable low doses of IFN-β significantly inhibited HCC growth whereas the same dose of IFN-α did not. IFN-β also significantly suppressed the tumor growth both in the p53-wild and p53-mutant HCC cells. Our in vitro study revealed that IFN-β showed a more potent inhibitory effect on the endothelial cell proliferation than IFN-α as in the in vivo study. Collectively, IFN may be an alternative anti-angiogenic agent against HCC since it exerted a significant tumoricidal effect regardless of the host p53 status even at a low dose. A cautious approach may be also required in the clinical practice since even in a same IFN subclass (class-I), IFN-α and IFN-β exert tumoricidal effects of different magnitudes on HCC
Selective aldosterone blocker ameliorates the progression of non-alcoholic steatohepatitis in rats.
Although non-alcoholic steatohepatitis (NASH) may progress to cirrhosis and hepatocellular carcinoma (HCC), no effective therapeutic modalities have been fully established yet. Recent studies have shown that the renin-angiotensin-aldosterone-system plays an important role in NASH. The aim of our current study was to elucidate the effects of aldosterone (Ald) inhibition on the progression of NASH. In the choline-deficient L-amino acid-defined diet-induced rat NASH model, the effects of a clinically used selective Ald blocker (SAB) were elucidated in conjunction with the activated hepatic stellate cells (HSC) and neovascularization, which are both known to play important roles in liver fibrosis development and hepatocarcinogenesis, respectively. Liver fibrosis development and the glutathione-S-transferase placental form-positive pre-neoplastic lesions were both markedly attenuated by SAB along with the suppression of the activated HSC and neovascularization. SAB inhibited the hepatic expression of transforming growth factor-β 1 and also that of the vascular endothelial growth factor. Our in vitro study showed that SAB also inhibited the Ald-induced HSC proliferation and in vitro angiogenesis in a dose-dependent manner. These results indicated that Ald plays a pivotal role in the progression of NASH. Considering that SAB is already widely used in clinical practice, this drug could represent a potential new strategy against NASH in the future
Losartan, an angiotensin-II type 1 receptor blocker, attenuates the liver fibrosis development of non-alcoholic steatohepatitis in the rat
<p>Abstract</p> <p>Background</p> <p>Apart from simple steatosis, the non-alcoholic steatohepatitis (NASH) can progress into liver fibrosis and cirrhosis. To date, however, no widely accepted therapeutic modalities have been established against NASH in the clinical practice. To find out promising new therapeutic agents, it is important to employ an appropriate experimental model of NASH, such as association with insulin resistance.</p> <p>Findings</p> <p>In the current study, we found that losartan, a clinically used angiotensin-II type 1 receptor blocker, significantly attenuated a choline-deficient L-amino acid-defined (CDAA) diet-induced steatohepatitis in obese diabetic- and insulin resistance-associated Otsuka Long-Evans Tokushima Fatty (OLETF) rats. The transforming growth factor-beta, a well-known major fibrogenic cytokine, was also suppressed in a similar magnitude to that of the fibrosis area. Noteworthy was the finding that these inhibitory effects were achieved even at a clinically comparable low dose.</p> <p>Conclusion</p> <p>Since losartan is widely used without serious side effects in the clinical practice, this agent may be an effective new therapeutic strategy against NASH.</p
Development of hepatocellular carcinoma in a patient 13 years after sustained virological response to interferon against chronic hepatitis C: a case report
The ASTRO-H X-ray Observatory
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly
successful X-ray missions initiated by the Institute of Space and Astronautical
Science (ISAS). ASTRO-H will investigate the physics of the high-energy
universe via a suite of four instruments, covering a very wide energy range,
from 0.3 keV to 600 keV. These instruments include a high-resolution,
high-throughput spectrometer sensitive over 0.3-2 keV with high spectral
resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in
the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers
covering 5-80 keV, located in the focal plane of multilayer-coated, focusing
hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12
keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and
a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the
40-600 keV band. The simultaneous broad bandpass, coupled with high spectral
resolution, will enable the pursuit of a wide variety of important science
themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical
Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to
Gamma Ray
The Quiescent Intracluster Medium in the Core of the Perseus Cluster
Clusters of galaxies are the most massive gravitationally-bound objects in
the Universe and are still forming. They are thus important probes of
cosmological parameters and a host of astrophysical processes. Knowledge of the
dynamics of the pervasive hot gas, which dominates in mass over stars in a
cluster, is a crucial missing ingredient. It can enable new insights into
mechanical energy injection by the central supermassive black hole and the use
of hydrostatic equilibrium for the determination of cluster masses. X-rays from
the core of the Perseus cluster are emitted by the 50 million K diffuse hot
plasma filling its gravitational potential well. The Active Galactic Nucleus of
the central galaxy NGC1275 is pumping jetted energy into the surrounding
intracluster medium, creating buoyant bubbles filled with relativistic plasma.
These likely induce motions in the intracluster medium and heat the inner gas
preventing runaway radiative cooling; a process known as Active Galactic
Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus
cluster core, which reveal a remarkably quiescent atmosphere where the gas has
a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from
the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s
is found across the 60 kpc image of the cluster core. Turbulent pressure
support in the gas is 4% or less of the thermodynamic pressure, with large
scale shear at most doubling that estimate. We infer that total cluster masses
determined from hydrostatic equilibrium in the central regions need little
correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July
Hitomi (ASTRO-H) X-ray Astronomy Satellite
The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month
The Mechanisms for Business Ecosystem Members to Capture Part of a Business Ecosystem’s Joint Created Value
Research into business ecosystems has rarely examined the success of business ecosystem members. Business ecosystem leaders tend to focus on their own success rather than carefully monitoring the success of business ecosystem members, and each member must find a mechanism to capture part of the business ecosystem’s joint created value. This study examines the mechanisms by which business ecosystem members capture part of a business ecosystem’s joint created value in the cases of linear tape open (LTO) ecosystems and how these mechanisms contribute to the sustainability of a business ecosystem. A case study was conducted with a review of both the author’s experience with Sony and third-party resources. We confirm the results by panel data analysis. We identified three mechanisms. First, a business ecosystem member can establish a new business ecosystem on their own through newly created complementary innovation. Essentially, a business ecosystem member can become a business ecosystem leader in a new business ecosystem. Second, a business ecosystem member gains market shares from technology leadership, the experience of mass production, and collaboration with the business ecosystem leader. Third, a business ecosystem member who creates complementary innovations can obtain patent royalties. These mechanisms help business ecosystem members stay within business ecosystems and contribute to its success and sustainability
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