Browsing by Author "Lizama, Carlos"

Now showing 1 - 9 of 9
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    Calcium (Ca2+) waves data calibration and analysis using image processing techniques
    (2013) Milovic Fabregat, Carlos Andrés; Oses, Carolina; Villalón, Manuel J.; Uribe Arancibia, Sergio A.; Prieto Vásquez, Claudia; Andía Kohnenkampf, Marcelo Edgardo; Irarrázaval Mena, Pablo; Tejos Núñez, Cristián Andrés; Lizama, Carlos
    Abstract Background Calcium (Ca2+) propagates within tissues serving as an important information carrier. In particular, cilia beat frequency in oviduct cells is partially regulated by Ca2+ changes. Thus, measuring the calcium density and characterizing the traveling wave plays a key role in understanding biological phenomena. However, current methods to measure propagation velocities and other wave characteristics involve several manual or time-consuming procedures. This limits the amount of information that can be extracted, and the statistical quality of the analysis. Results Our work provides a framework based on image processing procedures that enables a fast, automatic and robust characterization of data from two-filter fluorescence Ca2+ experiments. We calculate the mean velocity of the wave-front, and use theoretical models to extract meaningful parameters like wave amplitude, decay rate and time of excitation. Conclusions Measurements done by different operators showed a high degree of reproducibility. This framework is also extended to a single filter fluorescence experiments, allowing higher sampling rates, and thus an increased accuracy in velocity measurements.
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    Concanavalin-A Induces Granulosa Cell Death and Inhibits FSH-Mediated Follicular Growth and Ovarian Maturation in Female Rats
    (2013) Velásquez Opazo, Ethel Virginia; Ríos Raggio, Mariana; Ortíz Scarlazetta, María Elena; Lizama, Carlos; Orge, Felipe; Oliva, Barbara; Orellana Walden, Renán Felipe; Villalón, Manuel J.; Moreno Mauro, Ricardo D.; Owen, Gareth Ivor; Núñez, Elizabeth; Abramovich, Dalhia; Tesone, Marta, Rokka, Anne; Corthals, Garry; Croxatto A., Horacio; Parborell, Fernanda
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    Deficient Vitamin E Uptake During Development Impairs Neural Tube Closure in Mice Lacking Lipoprotein Receptor SR-BI
    (2017) Santander Grez, Nicolás Guillermo; Lizama, Carlos; Parga Ponce, María José; Quiroz Vallverdu, Alonso Ingmar; Pérez Pons, Druso Diego; Echeverría Errázuriz, Guadalupe; Ulloa, Lorena; Palma, Verónica; Rigotti Rivera, Attilio; Busso, Dolores
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    Developmental abnormalities in mouse embryos lacking the HDL receptor SR-BI
    (2013) Santander, Nicolás Guillermo; Contreras Duarte, Susana de las Mercedes; Awad, María Fernanda; Lizama, Carlos; Passalacqua, Isabella; Rigotti Rivera, Attilio; Busso, Dolores
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    Etoposide induces apoptosis and upregulation of TACE/ADAM17 and ADAM10 in an in vitro male germ cell line model
    (2011) Lizama, Carlos; Ludwig, Andreas; Moreno, Ricardo D.
    Etoposide is a widely used anticancer drug in the treatment of different tumors. Etoposide is known to activate a wide range of intracellular signals, which may in turn induce cellular responses other than apoptosis. ADAM10 and TACE/ADAM17 belong to a family of transmembrane extracellular metalloproteinases involved in paracrine/juxtacrine regulation of many signaling pathways. The aim of this work was to evaluate if etoposide induces upregulation of ADAM10 or TACE/ADAM17 in two cell lines (GC-1 and GC-2) derived from male germ cells. Results showed that etoposide induced apoptosis in a dose-response manner in both GC-1 and GC-2 cells. Apoptosis started to increase 6 h after etoposide addition in GC-2 cells, whereas the same was observed 18 h after addition to the GC-1 cells. Protein and mRNA levels of ADAM10 and TACE/ADAM17 increased 18.h after etoposide was removed from the GC-1 cells. In GC-2 cells, the protein levels of both proteins increased 12 h after etoposide was removed. ADAM] 0 mRNA increased after 3 h and then steadily decreased up to 12 h after removal, whereas TACE/ADAM17 mRNA decreased after etoposide removal. Finally, apoptosis was prevented in GC-1 and GC-2 cells by the addition of pharmacological inhibitors of ADAM10 and TACE/ADAM17 to the culture medium of etoposide-treated cells. Our results show for the first time that etoposide upregulates ADAM10 and TACE/ADAM17 mRNA and protein levels. In addition, we also show that ADAM] 0 and TACE/ADAM17 have a role in etoposide-induced apoptosis. (c) 2010 Elsevier B.V. All rights reserved.
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    Maximal Regularity for Flexible Structural Systems in Lebesgue Spaces
    (HINDAWI LTD, 2010) Fernandez, Claudio; Lizama, Carlos; Poblete, Veronica
    We study abstract equations of the form lambda u'''(t) + u"(t) = c(2) Au(t) + c(2)mu Au'(t) + f (t), 0 < lambda < mu which is motivated by the study of vibrations of flexible structures possessing internal material damping. We introduce the notion of (alpha;beta;gamma)-regularized families, which is a particular case of (a; k)-regularized families, and characterize maximal regularity in L-p-spaces based on the technique of Fourier multipliers. Finally, an application with the Dirichlet-Laplacian in a bounded smooth domain is given.
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    Mitotic Inheritance of mRNA Facilitates Translational Activation of the Osteogenic-Lineage Commitment Factor Runx2 in Progeny of Osteoblastic Cells
    (2016) Varela Figueroa, Nelson; Aránguiz Quezada, Katherine Alejandra; Lizama, Carlos; Sepúlveda, Hugo; Antonelli Anativia, Juan; Thaler, Román; Moreno Mauro, Ricardo D.; Montecino, Martín; Stein, Gary S.; Van Wijnen, Andre; Galindo Díaz, Mario
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    Regularity of solutions for a third order differential equation in Hilbert spaces
    (ELSEVIER SCIENCE INC, 2011) Fernandez, Claudio; Lizama, Carlos; Poblete, Veronica
    We study regularity of mild and strong solutions of an abstract mathematical model of a flexible space structure under appropriate initial conditions. We apply our results showing qualitative properties of the trajectories in the case of the negative Laplacian operator. (C) 2011 Elsevier Inc. All rights reserved.
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    Spermatozoa from mice deficient in Niemann-Pick disease type C2 (NPC2) protein have defective cholesterol content and reduced in vitro fertilising ability
    (2014) Busso, Dolores; Oñate Alvarado, María José; Balboa Castillo, Elisa Ivana; Castro, Juan; Lizama, Carlos; Morales, Gabriela; Vargas, Susana; Härtel, Steffen; Moreno Mauro, Ricardo D.; Zanlungo Matsuhiro, Silvana