Disruption of e-cadherin junctional integrity in ovarian cancer cells is promoted by LPA-induced MMP-9 activity [abstract]

Approximately 22,000 U.S. women are newly diagnosed each year with epithelial ovarian cancer (EOC), 75% of whom present with existing metastases and peritoneal ascites. A key event in EOC metastasis is disruption of cell-cell contacts via modulation of intercellular junctional components such as cadherins. In contrast to most carcinomas, EOC actually gain expression of the cell-cell adhesion molecule Ecadherin. Ovarian cancer metastasizes via exfoliation of cells from the primary tumor to the peritoneal cavity, wherein free-floating cells and multi-cellular aggregates attach and invade to anchor growth of secondary lesions. Ascites is also rich in lysophosphatidic acid (LPA), a bioactive lipid that is a sensitive biomarker for ovarian cancer and may promote early events in ovarian cancer dissemination. The objective of this study was to determine whether LPA modulates E-cadherin junctional integrity. Immunofluorescence analyses were used to demonstrate a loss of junctional E-cadherin in OvCar3, OvCa429 and OvCa433cells exposed to LPA. LPA-induced loss of E-cadherin was concentration-and time-dependent. Surface labeling and western blotting showed that LPA promoted E-cadherin ectodomain shedding. Matrix metalloproteinase-9 (MMP9) expression was also induced by LPA treatment and inhibition of MMP9 activity blocked E-cadherin ectodomain shedding. Blocking LPA receptor signaling using the compound LPAR1 inhibited MMP9 expression and restored junctional E-cadherin staining. These data support a model wherein LPA induces MMP9 expression and MMP9-catalyzed E-cadherin ectodomain shedding, resulting in a loss of E-cadherin junctional integrity, facilitating metastatic dissemination of ovarian cancer cells

A Comparison Study of Using Origami as a Teaching Tool in Middle-School Mathematics Class in North America and China

This Major Paper compares origami-based mathematics school activities in North America and China. It introduces the current situation of the use of origami in mathematics classes to identify the similarities and differences of using origami as a teaching approach in these two regions. The Paper also attempts the analysis from various perspectives, including mathematics reform, mathematics learning system and environment, as well as the benefits of using origami in mathematics class, and how it relates to students’ mathematics achievement. Both North American and Chinese mathematics educators’ focus on integrating origami into middle schools’ mathematics classes can be found in the study.Some same or similar origami activities are used in the two regions; however, origami in Chinese classes is more often used as an auxiliary teaching activity, while teachers in North America also teach origami itself such as modular origami

Morphotropic Phase Boundary Engineering in Ferroelectrics

Barium calcium titanate (BCT), Sr-doped BCT (BSCT), and barium strontium calcium titanate-barium zirconate titanate xBSCT-(1-x)BZT (0.1&lex&le0.55) ceramics have been prepared by sol-gel method and solid state sintering process. The temperature dependences of dielectric constant and loss at different frequencies for all compositions were characterized and analyzed. For xBSCT-(1-x)BZT ceramics with 20% Ba in BCT substituted by Sr, the paraelectric-to-ferroelectric (cubic-to-tetragonal/rhombohedral) phase transition temperature TC increases for compositions of x0.28 with respect to the undoped xBCT-(1-x)BZT. Compared with BCT-BZT system, Sr-doped BSCT-BZT system shows a triple point at lower composition and temperature, and a morphotropic phase boundary (MPB) which is less vertical with respect to the composition axis in the phase diagram. Our results demonstrate that doping is an effective way to engineer MPB of BCT-BZT system and thus can help develop more compositions suitable for applications requiring large piezoelectric coefficient

Do ultrastructural changes in aged peritoneum contribute to ovarian cancer metastasis? [abstract]

Epithelial ovarian cancer (EOC) will affect 1 in 69 women born in the United States today. Currently, 80% of women newly diagnosed with EOC already have metastatic disease, thus early intervention during the metastatic process will improve the long-term survival rates of women with EOC. Metastasis in EOC occurs through a unique process where cells are shed from a primary tumor and form multicellular aggregates (MCA) that disseminate intraperitoneally in the ascites fluid

Apprenticeship Standard : Non-Destructive Testing Engineer

High-efficiency video compression technology is of primary importance to the storage and transmission of digital medical video in modern medical communication systems. To further improve the compression performance of medical ultrasound video, two innovative technologies based on diagnostic region-of-interest (ROI) extraction using the high efficiency video coding (H.265/HEVC) standard are presented in this paper. First, an effective ROI extraction algorithm based on image textural features is proposed to strengthen the applicability of ROI detection results in the H.265/HEVC quad-tree coding structure. Second, a hierarchical coding method based on transform coefficient adjustment and a quantization parameter (QP) selection process is designed to implement the otherness encoding for ROIs and non-ROIs. Experimental results demonstrate that the proposed optimization strategy significantly improves the coding performance by achieving a BD-BR reduction of 13.52% and a BD-PSNR gain of 1.16 dB on average compared to H.265/HEVC (HM15.0). The proposed medical video coding algorithm is expected to satisfy low bit-rate compression requirements for modern medical communication systems

Lysophoshatidic acid regulation of cell surface-associated proteases

Abstract only availableLysophosphatidic acid (LPA) is a potential biomarker of ovarian cancer and is thought to promote early stages of cancer progression through the stimulation of two cell surface associated proteases. The affects of LPA on the expression and cell surface association of two proteolytic enzymes associated with ovarian cancer progression, matrix metalloproteinase-9 (MMP-9) and urokinase-type plasminogen activator (uPA), were analyzed. Both MMP-9 and uPA have been linked with cancer cell invasion due to their proteolytic activity. The cell surface association and activation of MMP-9 is a chief mechanism by which cells invade collagen rich barriers, whereas the increased binding of uPA to its cell surface receptor promotes the conversion of plasminogen to plasmin which also promotes cell invasion. LPA was shown to increase the expression of the MMP-9 protease in a concentration dependent manner in both OVCA 429 and OVCA 433 ovarian cancer cell cultures at concentrations well below those normally found in ascites fluids ( 1 M). LPA treatment (80 M) showed as much as a 3.5 fold increase in MMP-9 expression. Further, LPA treatment increased the expression of MMP-9 over MMP-2 in conditioned media of both OVCA 429 and OVCA 433 cells. Stimulation of uPA activity was also shown in culture medium but required the elevated concentrations ( 20 M) often found in the ascites of ovarian cancer patients. Inhibitor studies showed that inhibition of PI-3K signaling (most evidently in OVCA 433 cells) and p38 MAPK (namely in OVCA 429 cells) repressed LPA stimulation of MMP-9 expression in a dose-dependent fashion. Future studies involving matrigel invasion assays will evaluate the functional consequence of LPA-stimulated MMP-9 expression and enhanced cell surface proteolysis on ovarian cancer cell invasive activity.NIH grant to M.S Stac

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With the help of a stochastic bounded real lemma, we deal with finite horizon H2/H∞ control problem for discrete-time MJLS, whose Markov chain takes values in an infinite set. Besides, a unified control design for H2, H∞, and H2/H∞ is given

Enhanced Group Delay of the Pulse Reflection with Graphene Surface Plasmon via Modified Otto Configuration

In this paper, the group delay of the transverse magnetic (TM) polarized wave reflected from a modified Otto configuration with graphene surface plasmon is investigated theoretically. The findings show that the optical group delay in this structure can be enhanced negatively and can be switched from negative to positive due to the excitation of surface plasmon by graphene. It is clear that the negative group delay can be actively tuned through the Fermi energy of the graphene. Furthermore, the delay properties can also be manipulated by changing either the relaxation time of graphene or the distance between the coupling prism and the graphene. These tunable delay characteristics are promising for fabricating grapheme-based optical delay devices and other applications in the terahertz regime

Lysophosphatidic Acid Disrupts Junctional Integrity and Epithelial Cohesion in Ovarian Cancer Cells

Ovarian cancer metastasizes via exfoliation of free-floating cells and multicellular aggregates from the primary tumor to the peritoneal cavity. A key event in EOC metastasis is disruption of cell-cell contacts via modulation of intercellular junctional components including cadherins. Ascites is rich in lysophosphatidic acid (LPA), a bioactive lipid that may promote early events in ovarian cancer dissemination. The objective of this paper was to assess the effect of LPA on E-cadherin junctional integrity. We report a loss of junctional E-cadherin in OVCAR3, OVCA429, and OVCA433 cells exposed to LPA. LPA-induced loss of E-cadherin was concentration and time dependent. LPA increased MMP-9 expression and promoted MMP-9-catalyzed E-cadherin ectodomain shedding. Blocking LPA receptor signaling inhibited MMP-9 expression and restored junctional E-cadherin staining. LPA-treated cells demonstrated a significant decrease in epithelial cohesion. Together these data support a model wherein LPA induces MMP-9 expression and MMP-9-catalyzed E-cadherin ectodomain shedding, resulting in loss of E-cadherin junctional integrity and epithelial cohesion, facilitating metastatic dissemination of ovarian cancer cells