195 research outputs found
Trehalose, an mTOR Independent Autophagy Inducer, Alleviates Human Podocyte Injury after Puromycin Aminonucleoside Treatment
published_or_final_versio
Immunotherapy of breast cancer by single delivery with rAAV2-mediated interleukin-15 expression
[[abstract]]Recombinant adenovirus-associated vector serotype 2 (rAAV2) is one of the most promising gene transfer vectors due to its advantage of causing non-pathogenic infection, low immunogenicity, and long-term gene expression in human clinical trials. Human interleukin 15 (hIL15) has been implicated in modulation of antitumor activity of lymphokine-activated killer (LAK) cells, including T cells and NK cells. In this study, the rAAV2-hIL15 vector was produced and subjected for treatment with xenograft JC breast cancer model. Results showed that tumor onset was significantly delayed, the tumor growth was suppressed, and the lifespan of tumor-bearing mice were prolonged by rAAV2-h1L15. In addition, rAAV2-hIL15 was able to produce a substantial expression of IL15 protein that ultimately activated the cytotoxic activity of LAK cells. Furthermore, prominent apoptosis was observed in tumor lesions following injection of rAAV2-hIL15. Taken together, our results suggested that rAAV2-hIL15 appears as a new potential therapeutic tool for breast cancer immunotherapy
Extended O-6-Methylguanine Methyltransferase Promoter Hypermethylation Following n-Butylidenephthalide Combined with 1,3-Bis(2-chloroethyl)-1-nitrosourea (BCNU) on Inhibition of Human Hepatocellular Carcinoma Cell Growth
[[abstract]]Epigenetic alteration of DNA methylation plays an important role in the regulation of gene expression associated with chemosensitivity of human hepatocellular (HCC) carcinoma cells. With the aim of improving the chemotherapeutic efficacy for HCC, the effect of the naturally occurring compound n-butylidenephthalide (BP), which is isolated from a chloroform extract of Angelica sinensis, was investigated. In both HepG2 and J5 HCC cell lines, a synergistic antiproliferative effect was observed when a low dosage of BP was combined with the chemotherapeutic drug 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). BCNU is an alkylating agent, and it prompts us to examine one of DNA repair genes, O-6-methylguanine methyltransferase (MGMT). It was evident from methylation-specific polymerase chain reaction (PCR) analysis that BP/BCNU combined treatment caused a time- and concentration-dependent enhancement of MGMT promoter methylation. Overexpression of MGMT could abolish BP-induced growth inhibition in the J5 tumor cell line as measured by colony formation assay. When BP was combined with BCNU and administered, it showed significant antitumor effects in both HepG2 and J5 xenograft tumors as compared with the use of only one of these drugs. The BCNU-induced apoptosis and inhibited MGMT protein expression in HCC cells, both in vitro and in vivo, resulting from the combination treatment of BP and BCNU suggest a potential clinical use of this compound for improving the prognosis for HCCs
Trehalose alleviates human podocyte injury via the induction of autophagy in an mTOR independent manner
Conference Theme: Excellence through collaborationThis journal issue contain abstracts of the 12th Asian Congress of Pediatric Nephrology (pp.2425-2445)postprin
Earth as a Proxy Exoplanet: Deconstructing and Reconstructing Spectrophotometric Light Curves
Point-source spectrophotometric (single-point) light curves of Earth-like planets contain a surprising amount of information about the spatial features of those worlds. Spatially resolving these light curves is important for assessing time-varying surface features and the existence of an atmosphere, which in turn is critical to life on Earth and significant for determining habitability on exoplanets. Given that Earth is the only celestial body confirmed to harbor life, treating it as a proxy exoplanet by analyzing time-resolved spectral images provides a benchmark in the search for habitable exoplanets. The Earth Polychromatic Imaging Camera (EPIC) on the Deep Space Climate Observatory (DSCOVR) provides such an opportunity, with observations of ~5000 full-disk sunlit Earth images each year at 10 wavelengths with high temporal frequency. We disk-integrate these spectral images to create single-point light curves and decompose them into principal components (PCs). Using machine-learning techniques to relate the PCs to six preselected spatial features, we find that the first and fourth PCs of the single-point light curves, contributing ~83.23% of the light-curve variability, contain information about low and high clouds, respectively. Surface information relevant to the contrast between land and ocean reflectance is contained in the second PC, while individual land subtypes are not easily distinguishable (<0.1% total light-curve variation). We build an Earth model by systematically altering the spatial features to derive causal relationships to the PCs. This model can serve as a baseline for analyzing Earth-like exoplanets and guide wavelength selection and sampling strategies for future observations
Photolysis of sulphuric acid as the source of sulphur oxides in the mesosphere of Venus
The sulphur cycle plays fundamental roles in the chemistry and climate of Venus. Thermodynamic equilibrium chemistry at the surface of Venus favours the production of carbonyl sulphide and to a lesser extent sulphur dioxide. These gases are transported to the middle atmosphere by the Hadley circulation cell. Above the cloud top, a sulphur oxidation cycle involves conversion of carbonyl sulphide into sulphur dioxide, which is then transported further upwards. A significant fraction of this sulphur dioxide is subsequently oxidized to sulphur trioxide and eventually reacts with water to form sulphuric acid. Because the vapour pressure of sulphuric acid is low, it readily condenses and forms an upper cloud layer at altitudes of 60–70 km, and an upper haze layer above 70 km (ref. 9), which effectively sequesters sulphur oxides from photochemical reactions. Here we present simulations of the fate of sulphuric acid in the Venusian mesosphere based on the Caltech/JPL kinetics model, but including the photolysis of sulphuric acid. Our model suggests that the mixing ratios of sulphur oxides are at least five times higher above 90 km when the photolysis of sulphuric acid is included. Our results are inconsistent with the previous model results but in agreement with the recent observations using ground-based microwave spectroscopy and by Venus Express
Origin of acidic surface waters and the evolution of atmospheric chemistry on early Mars
Observations from in situ experiments and planetary orbiters have shown that the sedimentary rocks found at Meridiani Planum, Mars were formed in the presence of acidic surface waters. The water was thought to be brought to the surface by groundwater upwelling, and may represent the last vestiges of the widespread occurrence of liquid water on Mars. However, it is unclear why the surface waters were acidic. Here we use geochemical calculations, constrained by chemical and mineralogical data from the Mars Exploration Rover Opportunity, to show that Fe oxidation and the precipitation of oxidized iron (Fe^(3+)) minerals generate excess acid with respect to the amount of base anions available in the rocks present in outcrop. We suggest that subsurface waters of near-neutral pH and rich in Fe^(2+) were rapidly acidified as iron was oxidized on exposure to O_2 or photo-oxidized by ultraviolet radiation at the martian surface. Temporal variation in surface acidity would have been controlled by the availability of liquid water, and as such, low-pH fluids could be a natural consequence of the aridification of the martian surface. Finally, because iron oxidation at Meridiani would have generated large amounts of gaseous H_2, ultimately derived from the reduction of H_2O, we conclude that surface geochemical processes would have affected the redox state of the early martian atmosphere
Epidemiological risk factors for adult dengue in Singapore: an 8-year nested test negative case control study
10.1186/s12879-016-1662-4BMC Infectious Diseases16132
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