21 research outputs found
Mechanism of Action of Two Flavone Isomers Targeting Cancer Cells with Varying Cell Differentiation Status
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Apoptosis can be triggered in two different ways, through the intrinsic or the extrinsic pathway. The intrinsic pathway is mediated by the mitochondria via the release of cytochrome C while the extrinsic pathway is prompted by death receptor signals and bypasses the mitochondria. These two pathways are closely related to cell proliferation and survival signaling cascades, which thereby constitute possible targets for cancer therapy. In previous studies we introduced two plant derived isomeric flavonoids, flavone A and flavone B which induce apoptosis in highly tumorigenic cancer cells of the breast, colon, pancreas, and the prostate. Flavone A displayed potent cytotoxic activity against more differentiated carcinomas of the colon (CaCo-2) and the pancreas (Panc28), whereas flavone B cytotoxic action is observed on poorly differentiated carcinomas of the colon (HCT 116) and pancreas (MIA PaCa). Apoptosis is induced by flavone A in better differentiated colon cancer CaCo-2 and pancreatic cancer Panc 28 cells via the intrinsic pathway by the inhibition of the activated forms of extracellular signal-regulated kinase (ERK) and pS6, and subsequent loss of phosphorylation of Bcl-2 associated death promoter (BAD) protein, while apoptosis is triggered by flavone B in poorly differentiated colon cancer HCT 116 and MIA PaCa pancreatic cancer cells through the extrinsic pathway with the concomitant upregulation of the phosphorylated forms of ERK and c-JUN at serine 73. These changes in protein levels ultimately lead to activation of apoptosis, without the involvement of AKT
Mechanism of Action of Two Flavone Isomers Targeting Cancer Cells with Varying Cell Differentiation Status
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Apoptosis can be triggered in two different ways, through the intrinsic or the extrinsic pathway. The intrinsic pathway is mediated by the mitochondria via the release of cytochrome C while the extrinsic pathway is prompted by death receptor signals and bypasses the mitochondria. These two pathways are closely related to cell proliferation and survival signaling cascades, which thereby constitute possible targets for cancer therapy. In previous studies we introduced two plant derived isomeric flavonoids, flavone A and flavone B which induce apoptosis in highly tumorigenic cancer cells of the breast, colon, pancreas, and the prostate. Flavone A displayed potent cytotoxic activity against more differentiated carcinomas of the colon (CaCo-2) and the pancreas (Panc28), whereas flavone B cytotoxic action is observed on poorly differentiated carcinomas of the colon (HCT 116) and pancreas (MIA PaCa). Apoptosis is induced by flavone A in better differentiated colon cancer CaCo-2 and pancreatic cancer Panc 28 cells via the intrinsic pathway by the inhibition of the activated forms of extracellular signal-regulated kinase (ERK) and pS6, and subsequent loss of phosphorylation of Bcl-2 associated death promoter (BAD) protein, while apoptosis is triggered by flavone B in poorly differentiated colon cancer HCT 116 and MIA PaCa pancreatic cancer cells through the extrinsic pathway with the concomitant upregulation of the phosphorylated forms of ERK and c-JUN at serine 73. These changes in protein levels ultimately lead to activation of apoptosis, without the involvement of AKT
Dense Cranial Electroacupuncture Stimulation for Major Depressive Disorder—A Single-Blind, Randomized, Controlled Study
BACKGROUND: Previous studies suggest that electroacupuncture possesses therapeutic benefits for depressive disorders. The purpose of this study was to determine whether dense cranial electroacupuncture stimulation (DCEAS) could enhance the antidepressant efficacy in the early phase of selective serotonin reuptake inhibitor (SSRI) treatment of major depressive disorder (MDD). METHODS: In this single-blind, randomized, controlled study, patients with MDD were randomly assigned to 9-session DCEAS or noninvasive electroacupuncture (n-EA) control procedure in combination with fluoxetine (FLX) for 3 weeks. Clinical outcomes were measured using the 17-item Hamilton Depression Rating Scale (HAMD-17), Clinical Global Impression-severity (CGI-S), and Self-rating Depression Scale (SDS) as well as the response and remission rates. RESULTS: Seventy-three patients were randomly assigned to n-EA (n = 35) and DCEAS (n = 38), of whom 34 in n-EA and 36 in DCEAS group were analyzed. DCEAS-treated patients displayed a significantly greater reduction from baseline in HAMD-17 scores at Day 3 through Day 21 and in SDS scores at Day 3 and Day 21 compared to patients receiving n-EA. DCEAS intervention also produced a higher rate of clinically significant response compared to n-EA procedure (19.4% (7/36) vs. 8.8% (3/34)). The incidence of adverse events was similar in the two groups. CONCLUSIONS: DCEAS is a safe and effective intervention that augments the antidepressant efficacy. It can be considered as an additional therapy in the early phase of SSRI treatment of depressed patients. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN88008690
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
Synthesis and Characterization of Magnetic Cabides and Oxides Nanomaterials
The design and development of nanoparticles is of great interest in the current energy and electronic industry. However, based on the current materials available the production cost can be high with insignificant magnetic and mechanical properties. Specifically, rare-earth magnetic materials composed of neodymium and samarium are known for their high magnetic performance, however, due to the cost of development there is a need to develop a versatile and cost effective material. Alternatively, cobalt carbide nanomaterials have shown to be a promising alternative for rare-earth free magnets as they exhibit comparable properties as hexaferrite magnetic materials. The primary goal of this dissertation focuses on the development of nanoparticles for permeant magnetic, and magnetic refrigeration applications. The first part of this work focuses on the synthesis of cobalt carbide (CoxC, x=2,3) nanoparticles using a novel polyol synthesis method by introducing a small amount of Ru, Cu, or Au as nucleating agent. It was found that the morphology and magnetic properties of the as-synthesized CoxC nanoparticles change as a result of directional growth of nanoparticles using nucleating agents. Needle-like particle morphology ranges from 20-50 nm in width and as long as 1 µm in length were synthesized using Ru as nucleating agent. These particles exhibit magnetization saturation of 33.5 emu/g with a coercivity of 2870 Oe and a maximum energy product 1.92 MGOe (BHmax) observed. Particle morphology is a critical aspect in the development of magnetic nanoparticles as anisotropic particles have shown increased coercivity and magnetic properties. These CoxC nanomaterials have a higher maximum energy product compared to previous work providing further insight into the development of non-rare earth magnetic material.
The second part of this dissertation work focuses on the sol-gel synthesis of perovskite LaCaMnO3 (LCMO) nanomaterials. In this process, various chain lengths of polyethylene glycol (PEG) was added into a solution consisting of La, Ca, and Mn salts. The solution was left for the gelation process, and high temperature sintering to obtain the final product. By varying the polymer chain of the PEG, the size of the as synthesized LaCaMnO3 nanomaterials were altered. The as-synthesized LCMO nanomaterials have shown a maximum change in magnetic entropy (-ΔSM) was found to be 19.3 Jkg-1K-1 at 278 K for a field change of 0-3 T and 8.7 Jkg-1K-1 for a field change of 0-1 T. This is a significant improvement in comparison to current literature of the material suggesting that this is a promising alternative to Gd materials that is prone to oxidation. With additional development, LCMO or related maganites could lead to application in commercial technologies
Integrated single-inductor dual-input dual-output boost converter for energy harvesting applications
An integrated single-inductor dual-input dual-output (SI DIDO) boost converter for energy harvesting applications was designed in a 0.35 mu m CMOS process. It provides two regulated output voltages for the load and the charge storage device, and two sources, the energy harvesting source and the charge storage device, are multiplexed to serve as the input. The implementation has several special features. (1) The input power MUX is driven by an internal charge pump for a larger gate drive to save area. (2) The power stage is implemented with an active diode core to eliminate gate drive circuitry. (3) A 1:7 timeslot scheduling with a fixed peak inductor current is adopted to deliver energy to the two outputs with a large difference in load currents. The proposed converter could operate at IV with up to 85% efficiency at 200 mW
Dense Cranial Electroacupuncture Stimulation for Major Depressive Disorder-A Single-Blind, Randomized, Controlled Study
Abstract Background: Previous studies suggest that electroacupuncture possesses therapeutic benefits for depressive disorders. The purpose of this study was to determine whether dense cranial electroacupuncture stimulation (DCEAS) could enhance the antidepressant efficacy in the early phase of selective serotonin reuptake inhibitor (SSRI) treatment of major depressive disorder (MDD)
Comparison of the effect of flavone A and flavone B on proliferative, and survival pathways.
<p>A and B: Detection of the activated and unphosphorylated forms of ERK, c-JUN, S6, AKT by immunoblot of total SDS extracts. Better differentiated Panc28 and CaCo 2 cells were treated with 40μM of flavone A (+A), and poorly differentiated MIA PaCa and HCT116 cells with flavone B (+B), or DMSO (-) the dissolution vehicle. After lysis and SDS-PAGE, membranes were probed with the indicated antibody. The membranes were reprobed for actin as a loading control, and a representative image is provided. The results shown are representative of three independent experiments. C and D: For quantification (graphs) the band densities from the treated/untreated conditions identified by (+) or (-), were normalized and calculated as percentages of the value for the untreated cells (100%), and shown averages ± standard deviations from three independent experiments (*p<0.05). E and F: Detection of phosphorylated ERK after treatment of CaCo 2 cells with flavone A and HCT116 cells with flavone B by immunofluorescence.</p
Analysis of downstream effector BAD after treatment with flavone A and flavone B.
<p>A and B: Detection of the loss of phosphorylation of BAD by immunoblot of total SDS extracts. Better differentiated Panc 28 and CaCo 2 cells were treated with 40μM of flavone A (+A), and poorly differentiated MIA PaCa and HCT116 cells with flavone B (+B), or DMSO (-) the dissolution vehicle. After lysis and SDS-PAGE, membranes were probed with an antibody specific to BAD phosphorylated at serine 112 or the unphosphorylated protein. The membranes were reprobed for actin as a loading control. The results shown are representative of three independent experiments. C and D: For quantification (graphs) the band densities from the treated/untreated conditions identified by (+) or (-), were normalized and calculated as percentages of the value for the untreated cells (100%), and shown averages ± standard deviations from three independent experiments (*p<0.05). E and F: Detection of phosphorylated BAD at serine 112 (red channel), after treatment of Panc 28 cells with flavone A and MIA PaCa cells with flavone B by immunofluorescence. Dapi (blue channel) was used to locate the nuclei.</p
Annexin V assay.
<p>Apoptotic effect of flavone A at a concentration of 40 μM, on the more differentiated pancreatic Panc28 and colon CaCo 2 cancer cells (Fig 1A and 1B), as determined by Annexin V assay (green channel) six hours after treatment. Dapi (blue channel) is used to locate the nuclei of the cells. Cells treated with vehicle only (DMSO at a final concentration of 0.27%) served as a control. Activation of apoptosis on the poorly differentiated pancreatic MIA PaCa and colon HCT116 cancer cells (Figs 1C and 1D) by flavone B at a concentration of 40 μM, as determined by Annexin V assay (green channel) six hours after treatment. Control conditions are the same as described above and Dapi was used to locate nuclei.</p