Browsing by Author "Mardones, Rodrigo"
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- ItemCHILE: ARE THE PARTIES OVER?(JOHNS HOPKINS UNIV PRESS, 2010) Pablo Luna, Juan; Mardones, Rodrigo
- ItemCultured autologous bone marrow stem cells inhibit bony fusion in a rabbit model of posterolateral lumbar fusion with autologous bone graft(ELSEVIER SCI LTD, 2010) Urrutia, Julio; Mery, Pablo; Martinez, Rafael; Pizarro, Felipe; Apablaza, Daniel; Mardones, RodrigoMesenchymal stem cells (MSCs) have been isolated from various tissues and expanded in culture. MSCs add osteogenic potential to ceramic scaffolds when used together. A spinal fusion rabbit model was used to evaluate whether a pellet of cultured, autologous bone marrow MSCs (BMSCs) with osteogenic differentiation could increase the fusion rate when co-grafted with an autologus bone graft compared to autograft alone. Thirty rabbits were randomly assigned to two groups. Group I received bone autograft alone and Group 2 received bone autograft plus a pellet of cultured and differentiated BMSCs. Group 2 rabbits had a bone marrow puncture, after which the BMSC were cultured and osteoblastic differentiation was induced. BMSC cultures were obtained from 12 of 15 rabbits. The 27 rabbits underwent a bilateral, L4-L5 intertransverse fusion with an autograft and in Group 2 rabbits a pellet of differentiated BMSCs was added to the autograft. In Group 1, the fusion rate was 53% (8 of 15 rabbits) and ill Group 2 the fusion rate was 0% (p < 0.05). Adding differentiated BMSCs in a pellet without a scaffold not only failed to increase fusion rate, but completely inhibited bony growth. (C) 2009 Elsevier Ltd. All rights reserved.
- ItemThe congressional politics of decentralization - The case of Chile(SAGE PUBLICATIONS INC, 2007) Mardones, RodrigoThis article explains why legislators in a centralized polity support decentralizing laws. Using Chile as a case study, it assesses two standard explanations for this support: party nomination procedures, which is disregarded; and electoral strategies, which is accepted. A novel finding is that party ideology is also a predictor of support for decentralization, with parties of the Right less likely to offer it. The author also argues that a legislator with a sub-national rather than national background is more likely to back such reforms in an attempt to enhance his or her reputation within the constituency. The author tests these and other hypotheses by combining qualitative arguments and regression analysis. The latter is performed on an original database of legislator biographical information, party electoral performance, regional CDP figures, and individual legislator support for 46 decentralizing laws approved in Chile between 1990 and 2006.
- ItemThe effect of ketoprophen on lumbar spinal fusion healing in a rabbit model(AMER ASSOC NEUROLOGICAL SURGEONS, 2007) Urrutia, Julio; Mardones, Rodrigo; Quezada, FelipeObject. Several reports have shown that nonsteroidal antiinflammatory drugs (NSAIDs) have an inhibitory effect in osteogenesis and reduce heterotopic ossification in humans. A deleterious effect of NSAIDs in posterolateral intertransverse process fusion has also been suggested. The authors used a validated rabbit model to try to determine the influence of the NSAID ketoprophen on the fusion rate in lumbar spinal arthrodesis.