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Search Results: 1 - 10 of 7365 matches for " Ruben Rene Gonzalez "
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Leptin’s Pro-Angiogenic Signature in Breast Cancer
Ruben Rene Gonzalez-Perez,Viola Lanier,Gale Newman
Cancers , 2013, DOI: 10.3390/cancers5031140
Abstract: Obesity is linked to increased incidence of breast cancer. The precise causes and mechanisms of these morbid relationships are unknown. Contradictory data on leptin angiogenic actions have been published. However, accumulating evidence would suggest that leptin’s pro-angiogenic effects in cancer play an essential role in the disease. Leptin, the main adipokine secreted by adipose tissue, is also abnormally expressed together with its receptor (OB-R) by breast cancer cells. Leptin induces proliferation and angiogenic differentiation of endothelial cells upregulates VEGF/VEGFR2 and transactivates VEGFR2 independent of VEGF. Leptin induces two angiogenic factors: IL-1 and Notch that can increase VEGF expression. Additionally, leptin induces the secretion and synthesis of proteases and adhesion molecules needed for the development of angiogenesis. Leptin’s paracrine actions can further affect stromal cells and tumor associated macrophages, which express OB-R and secrete VEGF and IL-1, respectively. A complex crosstalk between leptin, Notch and IL-1 (NILCO) that induces VEGF/VEGFR2 is found in breast cancer. Leptin actions in tumor angiogenesis could amplify, be redundant and/or compensatory to VEGF signaling. Current failure of breast cancer anti-angiogenic therapies emphasizes the necessity of targeting the contribution of other pro-angiogenic factors in breast cancer. Leptin’s impact on tumor angiogenesis could be a novel target for breast cancer, especially in obese patients. However, more research is needed to establish the importance of leptin in tumor angiogenesis. This review is focused on updated information on how leptin could contribute to tumor angiogenesis.
Leptin-signaling inhibition results in efficient anti-tumor activity in estrogen receptor positive or negative breast cancer
Ruben Rene Gonzalez, Amber Watters, Yanbo Xu, Udai P Singh, David R Mann, Bo R Rueda, Manuel L Penichet
Breast Cancer Research , 2009, DOI: 10.1186/bcr2321
Abstract: To test the contribution of leptin signaling to BC growth and expression of leptin-targeted molecules, PEG-LPrA2 treatment was applied to severe immunodeficient mice hosting established ER+ (MCF-7 cells; ovariectomized/supplemented with estradiol) and ER- (MDA-MB231 cells) BC xenografts. To further assess leptin and PEG-LPrA2 effects on ER+ and ER- BC, the expression of VEGF and VEGFR2 (protein and mRNA) was investigated in cell cultures.PEG-LPrA2 more effectively reduced the growth of ER+ (>40-fold) than ER- BC (twofold) and expression of pro-angiogenic (VEGF/VEGFR2, leptin/leptin receptor OB-R, and IL-1 receptor type I) and pro-proliferative molecules (proliferating cell nuclear antigen and cyclin D1) in ER+ than in ER- BC. Mouse tumor stroma in ER+ BC expressed high levels of VEGF and leptin that was induced by leptin signaling. Leptin upregulated the transcriptional expression of VEGF/VEGFR2 in MCF-7 and MDA-MB231 cells.These results suggest that leptin signaling plays an important role in the growth of both ER+ and ER- BC that is associated with the leptin regulation of pro-angiogenic and pro-proliferative molecules. These data provide support for the potential use of leptin-signaling inhibition as a novel treatment for ER+ and ER- BC.Leptin is a small nonglycosylated protein (16 kDa) product of the ob gene. White adipose tissue is the primary source of leptin in benign tissue, but leptin is also expressed and secreted by cancer cells [1]. Leptin exclusively binds to its receptor, OB-R. Several isoforms of OB-R are found in diverse tissues and in cancer cells including the long isoform, OB-Rb [2,3]. Upon leptin activation, the OB-R isoforms can utilize a number of diverse signaling pathways relevant to cancer growth [4,5]. The well-documented biological actions of leptin at the hypothalamic level occur through OB-Rb signals that are linked to the control of appetite and energy balance [4].Evidence is mounting to support the idea that leptin is the link between
The Political Economy of Sino-Peruvian Relations: A New Dependency?
Ruben Gonzalez-Vicente
Journal of Current Chinese Affairs , 2012,
Abstract: This article reviews dependency postulates and examines whether they are applicable to explain the political economy of China’s contemporary relations with Peru. It argues that the dichotomy between Peru as a commodity-providing periphery and China as a core manufacturing centre is insufficient to explain the ways in which power is embedded in the international economic system, and particularly inadequate to identify winners and losers in the international division of labour. Thereby, in line with some recent international political economy discussions of power, the article proposes that China should not be understood as a self-contained economic entity, but as a hub where natural resources are mobilized for transnational production. Furthermore, contending that a focus on nation-states fails to capture the complexity of (under)-development dynamics, it suggests that notions of internal colonialism, flexible sovereignties and postcolonial analyses of representation provide fresher perspectives from which to understand the distribution of power along the political economy of Sino-Peruvian relations.
Notch, IL-1 and Leptin Crosstalk Outcome (NILCO) Is Critical for Leptin-Induced Proliferation, Migration and VEGF/VEGFR-2 Expression in Breast Cancer
Shanchun Guo, Ruben R. Gonzalez-Perez
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0021467
Abstract: High levels of pro-angiogenic factors, leptin, IL-1, Notch and VEGF (ligands and receptors), are found in breast cancer, which is commonly correlated with metastasis and lower survival of patients. We have previously reported that leptin induces the growth of breast cancer and the expression of VEGF/VEGFR-2 and IL-1 system. We hypothesized that Notch, IL-1 and leptin crosstalk outcome (NILCO) plays an essential role in the regulation of leptin-mediated induction of proliferation/migration and expression of pro-angiogenic molecules in breast cancer. To test this hypothesis, leptin's effects on the expression and activation of Notch signaling pathway and VEGF/VEGFR-2/IL-1 were determined in mouse (4T1, EMT6 and MMT) breast cancer cells. Remarkably, leptin up-regulated Notch1-4/JAG1/Dll-4, Notch target genes: Hey2 and survivin, together with IL-1 and VEGF/VEGFR-2. RNA knockdown and pharmacological inhibitors of leptin signaling significantly abrogated activity of reporter gene-luciferase CSL (RBP-Jk) promoter, showing that it was linked to leptin-activated JAK2/STAT3, MAPK, PI-3K/mTOR, p38 and JNK signaling pathways. Interestingly, leptin upregulatory effects on cell proliferation/migration and pro-angiogenic factors Notch, IL-1 and VEGF/VEGFR-2 were abrogated by a γ-secretase inhibitor, DAPT, as well as siRNA against CSL. In addition, blockade of IL-1R tI inhibited leptin-induced Notch, Hey2 and survivin as well as VEGF/VEGFR-2 expression. These data suggest leptin is an inducer of Notch (expression/activation) and IL-1 signaling modulates leptin effects on Notch and VEGF/VEGFR-2. We show for the first time that a novel unveiled crosstalk between Notch, IL-1 and leptin (NILCO) occurs in breast cancer. Leptin induction of proliferation/migration and upregulation of VEGF/VEGFR-2 in breast cancer cells were related to an intact Notch signaling axis. NILCO could represent the integration of developmental, pro-inflammatory and pro-angiogenic signals critical for leptin-induced cell proliferation/migration and regulation of VEGF/VEGFR-2 in breast cancer. Targeting NILCO might help to design new pharmacological strategies aimed at controlling breast cancer growth and angiogenesis.
Pegylated interferon alpha-2b as adjuvant treatment of Stage III malignant melanoma: an evidence-based review
Sonia Okuyama, Rene Gonzalez, Karl D Lewis
Core Evidence , 2010, DOI: http://dx.doi.org/10.2147/CE.S8588
Abstract: ylated interferon alpha-2b as adjuvant treatment of Stage III malignant melanoma: an evidence-based review Review (3449) Total Article Views Authors: Sonia Okuyama, Rene Gonzalez, Karl D Lewis Published Date September 2010 Volume 2010:5 Pages 39 - 48 DOI: http://dx.doi.org/10.2147/CE.S8588 Sonia Okuyama, Rene Gonzalez, Karl D Lewis Division of Medical Oncology, Department of Cutaneous Oncology, University of Colorado, Denver, CO, USA Introduction: Stage III melanoma, also referred to as regional metastatic melanoma, has five-year survival rates ranging between 40% and 78%. In order to reduce the likelihood of recurrence in this high-risk population, patients undergo resection of primary tumors and all involved nodal basins. Systemic therapy is being pursued in an effort to improve outcome data, but the best strategy has yet to be defined. Interferon alpha-2b remains to date the most -promising approach available. Toxicities and intensive intravenous administration, unfortunately, are major -concerns. An alternative is the use of interferon in its pegylated subcutaneous form. The aim of this research was to review the evidence for the use of pegylated interferon alpha-2b in Stage III malignant melanoma. Evidence review: ECOG 1684 was the pivotal trial that first demonstrated a statistically significant benefit in relapse-free and overall survival for adjuvant interferon alpha-2b in high-risk melanoma. Other larger studies, such as ECOG 1690, confirmed a relapse-free survival benefit but did not achieve statistical significance for overall survival. The first study of the pegylated form of interferon alpha-2b in Stage III melanoma, EORTC 18991, is reviewed here. This trial showed a statistically significant improvement in relapse-free survival but not overall survival. Encouraging data of potential equivalent efficacy, easier administration, and fewer Grade 3 and 4 adverse reactions compared with high-dose intravenous interferon raises the question of its potential role in Stage III melanoma in the adjuvant setting.
Pegylated interferon alpha-2b as adjuvant treatment of Stage III malignant melanoma: an evidence-based review
Sonia Okuyama,Rene Gonzalez,Karl D Lewis
Core Evidence , 2010,
Abstract: Sonia Okuyama, Rene Gonzalez, Karl D LewisDivision of Medical Oncology, Department of Cutaneous Oncology, University of Colorado, Denver, CO, USAIntroduction: Stage III melanoma, also referred to as regional metastatic melanoma, has five-year survival rates ranging between 40% and 78%. In order to reduce the likelihood of recurrence in this high-risk population, patients undergo resection of primary tumors and all involved nodal basins. Systemic therapy is being pursued in an effort to improve outcome data, but the best strategy has yet to be defined. Interferon alpha-2b remains to date the most -promising approach available. Toxicities and intensive intravenous administration, unfortunately, are major -concerns. An alternative is the use of interferon in its pegylated subcutaneous form. The aim of this research was to review the evidence for the use of pegylated interferon alpha-2b in Stage III malignant melanoma.Evidence review: ECOG 1684 was the pivotal trial that first demonstrated a statistically significant benefit in relapse-free and overall survival for adjuvant interferon alpha-2b in high-risk melanoma. Other larger studies, such as ECOG 1690, confirmed a relapse-free survival benefit but did not achieve statistical significance for overall survival. The first study of the pegylated form of interferon alpha-2b in Stage III melanoma, EORTC 18991, is reviewed here. This trial showed a statistically significant improvement in relapse-free survival but not overall survival. Encouraging data of potential equivalent efficacy, easier administration, and fewer Grade 3 and 4 adverse reactions compared with high-dose intravenous interferon raises the question of its potential role in Stage III melanoma in the adjuvant setting.Keywords: pegylated interferon alpha-2b, melanoma, peg-interferon, adjuvant
Bismuth Effect on the Mechanical Properties of Antifriction Al-Sn Alloys  [PDF]
Isai Rosales, Gonzalo Gonzalez-Rodriguez, Jose Luis Gama, Rene Guardian
Materials Sciences and Applications (MSA) , 2014, DOI: 10.4236/msa.2014.55038
Abstract:

Al-Sn alloys were produced by the induction melting method with different Bi additions. Microstructure shows grains 130 μm average size. Fracture toughness and hardness tests have shown that ternary alloying elements present significantly affected the samples with Bi alloying. Plastic deformation was evaluated by using the forging test; the results have shown that the addition of 3.5 at.% Bi increased the value at least twice as compared with unalloyed sample. Wear test indicated that bismuth slightly affected the tribological behavior. It was found that a concentration of 3.0 at.% Bi, considerably enhances the alloys performance.

The Effect of Tin on PECVD-Deposited Germanium Sulfide Thin Films for Resistive RAM Devices  [PDF]
Rene Rodriguez, Benjamin Poulter, Mateo Gonzalez, Fadil Ali, Lisa D. Lau, McKenzie Mangun
Materials Sciences and Applications (MSA) , 2017, DOI: 10.4236/msa.2017.82012
Abstract: Resistive RAM is a promising, relatively new type of memory with fast switching characteristics. Metal chalcogenide films have been used as the amorphous semiconductor layer in these types of devices. The amount of crystallinity present in the films may be important for both reliable operation and increased longevity of the devices. Germanium sulfide films can be used for these devices, and a possible way to tune the crystalline content of the films is by substituting Sn for some of the Ge atoms in the film. Thin films of GexSnySz containing varying amounts of tin were deposited in a plasma enhanced chemical vapor deposition reactor. Films with 2%, 8%, 15%, 26%, and 34% atomic percentage Sn were deposited to determine crystallinity and structural information with XRD and Raman spectroscopy. Based on these depositions it was determined that at about 8% Sn content and below, the films were largely amorphous, and at about 26% Sn and above, they appeared to be largely crystalline. At 15% Sn composition, which is between 8% and 26%, the film is more a mixture of the two phases. Based on this information, current-voltage (IV) curves of simple memory switching devices were constructed at 5% Sn (in the amorphous region), at 25% Sn (in the crystalline region), and at 15% (in the mixed region). Based on the IV curves from these devices, the 15% composition gave the best overall switching behavior suggesting that a certain degree of order in the semiconductor layer is important for RRAM devices.
Interacting Phantom Energy and Avoidance of the Big Rip Singularity
Ruben Curbelo,Tame Gonzalez,Genly León,Israel Quiros
Physics , 2005, DOI: 10.1088/0264-9381/23/5/010
Abstract: Models of the universe with arbitrary (non gravitational) interaction between the components of the cosmic fluid: the phantom energy and the background, are investigated. A general form of the interaction that is inspired in scalar-tensor theories of gravity is considered. No specific model for the phantom fluid is assumed. We concentrate our investigation on solutions that are free of the coincidence problem. We found a wide region in the parameter space where the solutions are free of the big rip singularity also. Physical arguments, together with arguments based on the analysis of the observational evidence, suggest that phantom models without big rip singularity might be preferred by Nature.
Google+ or Google-?: Dissecting the Evolution of the New OSN in its First Year
Roberto Gonzalez,Ruben Cuevas,Reza Motamedi,Reza Rejaie,Angel Cuevas
Computer Science , 2012,
Abstract: In the era when Facebook and Twitter dominate the market for social media, Google has introduced Google+ (G+) and reported a significant growth in its size while others called it a ghost town. This begs the question that "whether G+ can really attract a significant number of connected and active users despite the dominance of Facebook and Twitter?". This paper tackles the above question by presenting a detailed characterization of G+ based on large scale measurements. We identify the main components of G+ structure, characterize the key features of their users and their evolution over time. We then conduct detailed analysis on the evolution of connectivity and activity among users in the largest connected component (LCC) of G+ structure, and compare their characteristics with other major OSNs. We show that despite the dramatic growth in the size of G+, the relative size of LCC has been decreasing and its connectivity has become less clustered. While the aggregate user activity has gradually increased, only a very small fraction of users exhibit any type of activity. To our knowledge, our study offers the most comprehensive characterization of G+ based on the largest collected data sets.
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