50 research outputs found
A 3,3’-Diiodothyronine Sulfate Cross-Reactive Material (Compound W), a Potential Marker for Fetal Hypothyroidism
CCN1 Induces β-Catenin Translocation in Esophageal Squamous Cell Carcinoma through Integrin α11
Aims. Nuclear translocation of β-catenin is common in many cancers including esophageal squamous cell carcinoma (ESCC). As a mediator of Wnt signaling pathway, nuclear β-catenin can activate many growth-related genes including CCN1, which in turn can induce β-catenin translocation. CCN1, a matricellular protein, signals through various integrin receptors in a cell-dependent manner to regulate cell adhesion, proliferation, and survival. Its elevation has been reported in ESCC as well as other esophageal abnormalities such as Barrett's esophagus. The aim of this study is to examine the relationship between CCN1 and β-catenin in ESCC. Methods and Results. The expression and correlation between CCN1 and β-catenin in ESCC tissue were examined through immunohistochemistry and further analyzed in both normal esophageal epithelial cells and ESCC cells through microarray, functional blocking and in situ protein ligation. We found that nuclear translocation of β-catenin in ESCC cells required high level of CCN1 as knockdown of CCN1 in ESCC cells reduced β-catenin expression and translocation. Furthermore, we found that integrin α11 was highly expressed in ESCC tumor tissue and functional blocking integrin α11 diminished CCN1-induced β-catenin elevation and translocation. Conclusions. Integrin α11 mediated the effect of CCN1 on β-catenin in esophageal epithelial cells
Texture-Etched SnO 2
Transparent electrodes of tin dioxide (SnO2) on glasses were further wet-etched in the diluted HCl:Cr solution to obtain larger surface roughness and better light-scattering characteristic for thin-film solar cell applications. The process parameters in terms of HCl/Cr mixture ratio, etching temperature, and etching time have been investigated. After etching process, the surface roughness, transmission haze, and sheet resistance of SnO2 glasses were measured. It was found that the etching rate was increased with the additions in etchant concentration of Cr and etching temperature. The optimum texture-etching parameters were 0.15 wt.% Cr in 49% HCl, temperature of 90°C, and time of 30 sec. Moreover, silicon thin-film solar cells with the p-i-n structure were fabricated on the textured SnO2 glasses using hot-wire chemical vapor deposition. By optimizing the texture-etching process, the cell efficiency was increased from 4.04% to 4.39%, resulting from the increment of short-circuit current density from 14.14 to 15.58 mA/cm2. This improvement in cell performances can be ascribed to the light-scattering effect induced by surface texturization of SnO2
Design, synthesis, and mechanism of action of 2-(3-hydroxy-5-methoxyphenyl)-6-pyrrolidinylquinolin-4-one as a potent anticancer lead
New 6- (or 6,7-) substituted 2-(hydroxyl substituted phenyl)quinolin-4-one derivatives were synthesized and screened for antiproliferative effects against cancer cell lines. Structure-activity relationship correlations were established and the most promising compound 2-(3-hydroxy-5-methoxyphenyl)-6-pyrrolidin-1-ylquinolin-4-one (6h) exhibited strong inhibitory activity against various human cancer cell lines, particularly non-small cell lung cancer NCI-H522. Additional studies suggested a mechanism of action resembling that of the antimitotic drug vincristine. The presence of a C-ring OH group in 6h will allow this compound to be converted readily to a water soluble and physiochemically stable hydrophilic prodrug. Compound 6h is proposed as a new anticancer lead compound
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Stimulation of liver iodothyronine monodeiodinases is not direct action of TSH
Thyroid and hepatic iodothyronine monodeiodinases were stimulated following THS treatment for 3 consecutive days in rats. It was questioned whether these thyroidal enzyme were induced secondarily by the elevated circulating thyroid hormone after TSH treatment or by a direct action of TSH. The present study showed that T3 treatment (25μg, t.i.d.) for 3 consecutive day markedly stimulated hepatic deiodinases; T3 conversion from T4 rose to 5.6-fold and T2 conversion from T3 rose to 3.7-fold of that in the saline control (P<0.0001 in both cases). Thyroid conversion of T4 to T3 and T3 to T2, on the other hand, decreased significantly after T 3 treatment. It is thus concluded that TSH-mediated induction of thyroid monodeiodinases is a direct effect of TSH; whereas the hepatic enzymes are stimulated secondarily by the increases of circulating thyroid hormones. It appears that iodothyronine monodeiodinases in the thyroid, which are readily inducible by TSH, may be important to an animal’s adaptation to hypothyroidism by activating the thyroid hormone. In contrast, liver having marked enzyme activity in hyperthyroidism and reduced enzyme activity in hypothyroidism my be important in deactivating the thyroid hormone (“detoxication”) in thyrotoxic states when the enzyme activity is high
A Homogeneous Time-Resolved Fluorescence Immunoassay Method for the Measurement of Compound W
Objective: Using compound W (a 3,3′-diiodothyronine sulfate [T 2 S] immuno-crossreactive material)-specific polyclonal antibodies and homogeneous time-resolved fluorescence immunoassay assay techniques (AlphaLISA) to establish an indirect competitive compound W (ICW) quantitative detection method. Method: Photosensitive particles (donor beads) coated with compound W or T 2 S and rabbit anti-W antibody were incubated with biotinylated goat anti-rabbit antibody. This constitutes a detection system with streptavidin-coated acceptor particle. We have optimized the test conditions and evaluated the detection performance. Results: The sensitivity of the method was 5 pg/mL, and the detection range was 5 to 10 000 pg/mL. The intra-assay coefficient of variation averages <10% with stable reproducibility. Conclusions: The ICW-AlphaLISA shows good stability and high sensitivity and can measure a wide range of compound W levels in extracts of maternal serum samples. This may have clinical application to screen congenital hypothyroidism in utero
Hot-wire chemical vapor deposition and characterization of polycrystalline silicon thin films using a two-step growth method
A two-step growth method was proposed to reduce the amorphous incubation layer in the initial growth of polycrystalline silicon (poly-Si) films prepared by hot-wire chemical vapor deposition (HWCVD). In the two-step growth process, a thin seed layer was first grown on the glass substrate under high hydrogen dilution ratios (φ ≥ 0.9), and then a thick overlayer was subsequently deposited upon the seed layer at a lower φ value. The effect of various deposition parameters on the structural properties of poly-Si films was investigated by Raman spectroscopy and transmission electron microscopy. Moreover, the electrical properties, such as dark and photo conductivities, of poly-Si films were also measured. It was found that the Si incubation layer could be suppressed greatly in the initial growth of poly-Si with the two-step growth method. In the subsequent poly-Si film thickening, a lower φ value of the reactant gases can be applied to enhance the deposition rate. Therefore, a high-quality poly-Si film can be fabricated via a two-step growth method with a sufficient growth rate using HWCVD