Browsing by Author "Chaparro, Alejandra"

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    Application of an incentive for bus drivers to achieve an improvement in the quality of service
    (Elsevier, 2020) Chaparro, Alejandra; Galilea Aranda, Patricia Viviana; Muñoz Abogabir, Juan Carlos; Poblete Lavanchy, Joaquín José; CEDEUS (Chile)
    Concession contracts of operating companies of the public transport system of Santiago, consider important fines if companies fail to comply with the operating plan, regularity and other operational variables included in those contracts. On the other hand, drivers receive a fixed payment with no pecuniary incentive related with their performance. The main objective of this paper is to analyze the application of a monetary incentive for bus drivers focused on increasing the number of passengers transported to test the existence of multitasking, specifically checking the behavior of drivers regarding bus speed. We conducted a field experiment with an operator of Transantiago and we used a difference in differences analysis to show that with the pecuniary incentive tested, drivers raised their transported passengers in 9% when riding in long bus routes. We found some evidence of multitasking associated with a decrease in speed of 3%. Thus, our research provides suggestive evidence that inefficiencies may be occurring in the operation because of the lack of adequate incentives for drivers.
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    CpG Single-Site Methylation Regulates TLR2 Expression in Proinflammatory PBMCs From Apical Periodontitis Individuals
    (FRONTIERS MEDIA SA, 2022) Bordagaray, Maria Jose; Fernandez, Alejandra; Astorga, Jessica; Garrido, Mauricio; Hernandez, Patricia; Chaparro, Alejandra; Lira, Maria Jesus; Gebicke-Haerter, Peter; Hernandez, Marcela
    IntroductionApical periodontitis (AP) is a common oral disease caused by the inflammatory destruction of the periapical tissues due to the infection of the root canal system of the tooth. It also contributes to systemic bacterial translocation, where peripheric mononuclear blood cells (PBMCs) can act as carriers. Toll-like receptor (TLR) 2 mediates the response to infection and activates inflammatory responses. DNA methylation can be induced by bacteria and contributes to the modulation of this response. Despite the evidence that supports the participation of PBMCs in immune-inflammatory disorders, the inflammatory profile and epigenetic regulatory mechanisms of PBMCs in AP individuals are unknown. AimTo determine TLR2 gene methylation and inflammatory profiles of PBMCs in AP. MethodsCross-sectional exploratory study. Otherwise, healthy individuals with AP (n=27) and controls (n=30) were included. PMBCs were isolated by a Ficoll gradient, cultured for 24 hours, and both RNA and DNA were extracted. DNA was bisulfite-treated, and specific sites at the promoter region of the TLR2 gene were amplified by qPCR using validated primers. To verify its amplification, agarose gels were performed. Then, the PCR product was sequenced. mRNA expression of TLR2 was determined by qPCR. The soluble levels of 105 inflammatory mediators were first explored with Proteome Profiler Human Cytokine Array Kit. Consequently, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-10, IL-6R alpha, IL-1 beta, and IL-12p70 levels were measured by Multiplex assay. ResultsPBMCs from individuals with AP demonstrated a proinflammatory profile showing higher soluble levels of TNF-alpha, IL-6, and IL-1 beta compared to controls (p<0.05). Higher TLR2 expression and higher global methylation pattern of the promoter region of the gene were found in AP compared to controls (p<0.05). The CpGs single-sites at positions -166 and -146 were completely methylated, while the site -102 was totally unmethylated, independently of the presence of AP. DNA methylation of CpG single-sites in positions -77 and +24 was positively associated with TLR2 expression. ConclusionsPBMCs from AP subjects show a hyperinflammatory phenotype and TLR2 upregulation in association with single CpG-sites' methylation from the TLR2 gene promoter, thereby contributing to a sustained systemic inflammatory load in individuals with periapical endodontic diseases.
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    Early pregnancy levels of gingival crevicular fluid matrix metalloproteinases-8 and-9 are associated with the severity of periodontitis and the development of gestational diabetes mellitus
    (2021) Chaparro, Alejandra; Realini, Ornella; Hernández, Marcela; Albers, Daniela; Weber, Laura; Ramírez, Valeria; Param, Fernanda; Kusanovic, Juan Pedro; Sorsa, Timo; Edward Rice, Gregory; Illanes, Sebastián E.
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    Elevated Systemic Inflammatory Burden and Cardiovascular Risk in Young Adults with Endodontic Apical Lesions
    (2019) Garrido, Mauricio; Cárdenas, Angélica María; Astorga, Jessica; Quinlan, Francisca; Valdés Salgado, Macarena; Chaparro, Alejandra; Carvajal, Paola; Pussinen, Pirkko; Huamán Chipana, Patricia; Jalil Milad, Jorge; Hernández, Marcela
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    Gingival Crevicular Placental Alkaline Phosphatase Is an Early Pregnancy Biomarker for Pre-Eclampsia
    (2021) Chaparro, Alejandra; Monckeberg, Maximiliano; Realini, Ornella; Hernandez, Marcela; Param, Fernanda; Albers, Daniela; Ramirez, Valeria; Pedro Kusanovic, Juan; Romero, Roberto; Rice, Gregory; Illanes, Sebastian E.
    Early and innovative diagnostic strategies are required to predict the risk of developing pre-eclampsia (PE). The purpose of this study was to evaluate the performance of gingival crevicular fluid (GCF) placental alkaline phosphatase (PLAP) concentrations to correctly classify women at risk of PE. A prospectively collected, retrospectively stratified cohort study was conducted, with 412 pregnant women recruited at 11-14 weeks of gestation. Physical, obstetrical, and periodontal data were recorded. GCF and blood samples were collected for PLAP determination by ELISA assay. A multiple logistic regression classification model was developed, and the classification efficiency of the model was established. Within the study cohort, 4.3% of pregnancies developed PE. GCF-PLAP concentration was 3- to 6-fold higher than in plasma samples. GCF-PLAP concentrations and systolic blood pressure were greater in women who developed PE (p = 0.015 and p < 0.001, respectively). The performance of the multiparametric model that combines GCF-PLAP concentration and the levels of systolic blood pressure (at 11-14 weeks gestation) showed an association of systolic blood pressure and GCF-PLAP concentrations with the likelihood of developing PE (OR:1.07; 95% CI 1.01-1.11; p = 0.004 and OR:1.008, 95% CI 1.000-1.015; p = 0.034, respectively). The model had a sensitivity of 83%, a specificity of 72%, and positive and negative predictive values of 12% and 99%, respectively. The area under the receiver operating characteristic (AUC-ROC) curve was 0.77 and correctly classified 72% of PE pregnancies. In conclusion, the multivariate classification model developed may be of utility as an aid in identifying pre-symptomatic women who subsequently develop PE.
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    Periodontitis and placental growth factor in oral fluids are early pregnancy predictors of gestational diabetes mellitus
    (2018) Chaparro, Alejandra; Zúñiga, Edgardo; Varas‐Godoy, Manuel; Albers, Daniela; Ramírez, Valeria; Hernández, Marcela; Kusanovic, Juan Pedro; Acuña‐Gallardo, Stephanie; Rice, Gregory; Illanes, Sebastián E.
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    Placental biomarkers and angiogenic factors in oral fluids of patients with preeclampsia
    (2016) Chaparro, Alejandra; Gaedechens, Dominique; Ramírez, Valeria; Zúñiga, Edgardo; Kusanovic, Juan Pedro; Inostroza, Carolina; Varas Godoy, Manuel; Silva, Karla; Salomon, Carlos; Rice, Gregory