Browsing by Author "Rojas, Carolina"

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    Capsular-defective Porphyromonas gingivalis mutant strains induce less alveolar bone resorption than W50 wild-type strain due to a decreased Th1/Th17 immune response and less osteoclast activity
    (2019) Monasterio, Gustavo; Fernandez, Baltasar; Castillo, Francisca; Rojas, Carolina; Cafferata, Emilio A.; Rojas, Leticia; Alvarez, Carla; Fernandez, Alejandra; Hernandez, Marcela; Bravo, Denisse; Vernal, Rolando
    Background Encapsulation of Porphyromonas gingivalis has been demonstrated as responsible of several host immunological changes, which have been associated with the pathogenesis of periodontitis. Using a murine model of periodontitis and two isogenic non-capsulated mutants of P. gingivalis, this study aimed to analyze whether P. gingivalis encapsulation induces more severe alveolar bone resorption, and whether this bone loss is associated with a T-helper (Th)1 and Th17-pattern of immune response. Methods Experimental periodontal infections were generated by oral inoculation with the encapsulated W50 wild-type strain or isogenic non-encapsulated Delta PG0116-PG0120 (GPA) and Delta PG0109-PG0118 (GPC) mutants of P. gingivalis. Periodontal infections induced with the encapsulated HG184 or non-encapsulated ATCC 33277 strains of P. gingivalis were used as controls. Alveolar bone resorption was analyzed using microcomputed tomography and scanning electron microscopy. The expression levels of Th1, Th2, Th17, or T regulatory-associated cytokines and RANKL, as well as the periodontal bacterial load, were quantified by quantitative polymerase chain reaction. The detection of Th1 and Th17 lymphocytes was analyzed by flow cytometry. Results In the periodontal lesions, both capsular-defective knockout mutant strains of P. gingivalis induced less alveolar bone resorption than the encapsulated W50 wild-type strain. This decreased bone loss was associated with a dismissed RANKL expression, decreased Th1- and Th17-type of cytokine expression, reduced Th1 and Th17 lymphocyte detection, and low osteoclast finding. Conclusion These data demonstrate that encapsulation of P. gingivalis plays a key role in the alveolar bone resorption induced during periodontitis, and this bone loss is associated with a Th1- and Th17-pattern of immune response triggered in the periodontal lesions.
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    Chronic Undernutrition in Ovine Twin Pregnancies Abolishes Differences in Birth Weight Due to Sex: An Evaluation of the Role of Nutritional and Antioxidant Supplementation
    (2024) Sales, Francisco; Peralta, oscar A.; de los Reyes, Monica; Sandoval, Camila; Martinez-Ros, Paula; Rojas, Carolina; Gonzales-Bulnes, Antonio; Parraguez, Victor H.
    Simple Summary The fetal growth pattern in twin pregnancies is usually affected by the sex of the co-twin pairs, among other factors, with females being lighter than males at birth. We aimed to determine the effect of the sex of co-twins on lambs' birth weight in ovine pregnancies developed under natural undernourishment, a condition of sheep farming frequently encountered worldwide. Additionally, we sought to investigate whether the nutritional and/or antioxidant supplementation provided to ewes during pregnancy could modulate the potential effects associated with the sex of co-twins. We found that maternal nutrient restriction abolishes the sex differences in body weight at birth between co-twins. However, improving maternal nutrition and supplementation with antioxidants during gestation not only improves maternal weight and body condition but also tends to restore birth weight and its differences between female and male offspring, an effect that is enhanced with the combined supplementation of concentrated food and antioxidants. These results suggest that undernutrition not only may alter the intrauterine growth through the maternal-fetal relationship, but also through the feto-fetal relationship, which can be normalized via strategically targeting interventions such as maternal nutrient supplementation or antioxidant supplementation during gestation. Thus, a better understanding of the driving factors of this effect is of major relevance to improving fetal growth and lamb survival in harsh environments.Abstract In twin pregnancies of discordant sex, the male fetus grows larger than the female co-twin. Our study aimed to determine the effect of the sex of co-twins on lambs' birth weight in ovine pregnancies developed under natural undernourishment. Additionally, we investigated whether the nutritional and/or antioxidant supplementation provided to ewes during pregnancy could modulate the potential effects associated with the sex of co-twins. Ninety-six birth records of twin pregnancies of sheep grazing the natural Patagonian prairies were analyzed. The animals were divided into four groups: control (no supplementation), N (concentrate supplementation, 100% NRC), A (antioxidant supplementation), and NA (concentrate + antioxidant supplementation). Supplementation occurred from day 35 of gestation onwards until lambing. There were no differences in female or male birth weight in the control undernourished group. However, in group N, females or males with sex-discordant co-twins had a higher birth weight than did those with co-twins of the same sex. Group A males with female co-twins had a higher birth weight compared to males whose co-twins were also males. In NA lambs, males had a higher birth weight compared to females, regardless of their co-twin's sex. Therefore, chronic undernutrition abolished the differences in birth weight due to fetal sex. Restoring maternal nutrition or antioxidant supplementation tends to normalize birth weight and restore the differences between females and males. This effect is enhanced with the combined supplementation of concentrated food and antioxidants.
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    Desalinización: oportunidades y desafíos para abordar la inseguridad hídrica en chile
    (Ministerio de Ciencia, Tecnología, Conocimiento e Innovación, 2022) Vicuña, Sebastián; Daniele, Linda; Farías, Laura; González, Humberto; Marquet, Pablo A.; Palma Behnke, Rodrigo; Stehr, Alejandra; Urquiza, Anahí; Wagemann, Elizabeth; Arenas Herrera, María J.; Bórquez, Rodrigo; Cornejo Ponce, Lorena; Delgado, Verónica; Etcheberry, Gabriel; Fragkou, María Christina; Fuster, Rodrigo; Gelcich, Stefan; Melo, Óscar; Monsalve, Tamara; Olivares, Marcelo; Ramajo, Laura; Ramírez Pascualli, Carlos; Rojas, Carolina; Rojas, Christian; Vilca Salinas, Patricia; Winckler, Patricio; Winckler, Patricio; Lambert, Fabrice
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    Regulatory T lymphocytes in periodontitis: a translational view
    (2018) Alvarez, Carla; Rojas, Carolina; Rojas Cortéz, Leticia Andrea; Cafferata, Emilio A.; Monasterio, Gustavo; Vernal, Rolando
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    Trends in household energy-related GHG emissions during COVID-19 in four Chilean cities
    (TAYLOR & FRANCIS LTD, 2022) Rojas, Carolina; Simon, Francois; Muniz, Ivan; Quintana, Marc; Irarrazaval, Felipe; Stamm, Caroline; Santos, Benedita; CEDEUS (Chile)
    The coronavirus disease 2019 (COVID-19) pandemic has strongly affected economies and human lifestyles globally. The changes observed in domestic energy consumption patterns have had an impact on household greenhouse gas (GHG) emissions. Since GHG emissions inventories are only available at the country level and at annual intervals, most studies have calculated the local emission variations by extrapolating annual emissions with smaller time and territorial scale consumption data. This research presents a bottom-up method, based on the exploitation of a survey addressed to 1200 households, that provides the information to calculate directly the variation in their energy-related GHG emissions, without the need for extrapolations. This method has been applied to four medium-sized Chilean cities with serious air quality problems. Given the high correlation between atmospheric pollutants such as NOx and CO2 emissions, we estimate that before the appearance of COVID-19, per capita CO2 emissions were already high. The results show that space heating-related GHG emissions have increased moderately (between 1 and 6%), while emissions from electricity and gas consumption for non-heating uses have increased significantly (between 8 and 23%). This has harmed the household economy, highlighting the importance of considering socioeconomic aspects when assessing the impact of COVID-19 in its entirety.
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    Urban development versus wetland loss in a coastal Latin American city : lessons for sustainable land use planning
    (2019) Rojas, Carolina; Munizaga, Juan; Rojas, Octavio; Martínez; Reyes, Carolina del Pilar; Pino, Joan; CEDEUS (Chile)
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    Urban Growth and Flood Disasters in the Coastal River Basin of South-Central Chile (1943–2011)
    (2017) Rojas, Octavio; Mardones, María; Rojas, Carolina; Martínez Reyes, Carolina del Pilar; Flores, Luis