Browsing by Author "Fuentes, Daniela"

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    A Deficiency in the Flavoprotein of Arabidopsis Mitochondrial Complex II Results in Elevated Photosynthesis and Better Growth in Nitrogen-Limiting Conditions
    (AMER SOC PLANT BIOLOGISTS, 2011) Fuentes, Daniela; Meneses, Marco; Nunes Nesi, Adriano; Araujo, Wagner L.; Tapia, Rodrigo; Gomez, Isabel; Holuigue, Loreto; Gutierrez, Rodrigo A.; Fernie, Alisdair R.; Jordana, Xavier
    Mitochondrial complex II (succinate dehydrogenase [SDH]) plays roles both in the tricarboxylic acid cycle and the respiratory electron transport chain. In Arabidopsis (Arabidopsis thaliana), its flavoprotein subunit is encoded by two nuclear genes, SDH1-1 and SDH1-2. Here, we characterize heterozygous SDH1-1/sdh1-1 mutant plants displaying a 30% reduction in SDH activity as well as partially silenced plants obtained by RNA interference. We found that these plants displayed significantly higher CO2 assimilation rates and enhanced growth than wild-type plants. There was a strong correlation between CO2 assimilation and stomatal conductance, and both mutant and silenced plants displayed increased stomatal aperture and density. By contrast, no significant differences were found for dark respiration, chloroplastic electron transport rate, CO2 uptake at saturating concentrations of CO2, or biochemical parameters such as the maximum rates of carboxylation by Rubisco and of photosynthetic electron transport. Thus, photosynthesis is enhanced in SDH-deficient plants by a mechanism involving a specific effect on stomatal function that results in improved CO2 uptake. Metabolic and transcript profiling revealed that mild deficiency in SDH results in limited effects on metabolism and gene expression, and data suggest that decreases observed in the levels of some amino acids were due to a higher flux to proteins and other nitrogen-containing compounds to support increased growth. Strikingly, SDH1-1/sdh1-1 seedlings grew considerably better in nitrogen-limiting conditions. Thus, a subtle metabolic alteration may lead to changes in important functions such as stomatal function and nitrogen assimilation.
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    Different Safety Pattern of an Inactivated SARS-CoV-2 Vaccine (CoronaVac®) According to Age Group in a Pediatric Population from 3 to 17 Years Old, in an Open-Label Study in Chile
    (2023) Le Corre, Nicole; Abarca Villaseca, Katia; Astudillo, Patricio André; Potin Santander, Marcela Patricia; López, Sofía; Goldsack, Macarena; Valenzuela Guerrero, Vania; Schilling Redlich, Andrea; Gaete, Victoria; Rubio, Lilian; Calvo, Mario; Twele, Loreto; González, Marcela; Fuentes, Daniela; Gutiérrez Muñoz, Valentina José; Reyes Zaldivar, Felipe Tomás; Tapia, Lorena I.; Villena, Rodolfo; Retamal Díaz, Angello; Cárdenas, Antonio; Alarcón Bustamante, Eduardo; Xin, Qianqian; González Aramundiz, José Vicente; Álvarez Figueroa, María Javiera; González Muñoz, Pablo Alberto; Bueno Ramírez, Susan; Soto Ramírez, Jorge Andrés; Perret Pérez, Cecilia; Meng, Xing; Kalergis Parra, Alexis Mikes
    During the COVID-19 pandemic, the importance of vaccinating children against SARS-CoV-2 was rapidly established. This study describes the safety of CoronaVac® in children and adolescents between 3- and 17-years-old in a multicenter study in Chile with two vaccine doses in a 4-week interval. For all participants, immediate adverse events (AEs), serious AEs (SAEs), and AEs of special interest (AESIs) were registered throughout the study. In the safety subgroup, AEs were recorded 28 days after each dose. COVID-19 surveillance was performed throughout the study. A total of 1139 individuals received the first and 1102 the second dose of CoronaVac®; 835 were in the safety subgroup. The first dose showed the highest number of AEs: up to 22.2% of participants reported any local and 17.1% systemic AE. AEs were more frequent in adolescents after the first dose, were transient, and mainly mild. Pain at the inoculation site was the most frequent AE for all ages. Fever was the most frequent systemic AE for 3–5 years old and headache in 6–17 years old. No SAEs or AESIs related to vaccination occurred. Most of the COVID-19 cases were mild and managed as outpatients. CoronaVac® was safe and well tolerated in children and adolescents, with different safety patterns according to age.
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    Safety and Non-Inferiority Evaluation of Two Immunization Schedules with an Inactivated SARS-CoV-2 Vaccine in Adults: A Randomized Clinical Trial
    Abarca Villaseca, Katia; Iturriaga Ortiz, Carolina Alejandra; Urzua, Marcela; Le Corre Perez, Monique Nicole; Pineda Núñez, Augusto Naim; Fernandez Anwandter, Carolina; Domínguez De Landa, María Angelica; González Carbonell, Pablo Andrés; Bueno, Susan M.; Donato, Paulina; Espinoza, Pilar; Fuentes, Daniela; Gonzalez, Marcela; Guzman, Paula; Munoz-Venturelli, Paula; Perez, Carlos M.; Potin, Marcela; Rojas, Alvaro; Gonzalez-Aramundiz, Jose, V; Galvez, Nicolas M. S.; Aguirre-Boza, Francisca; Aljaro, Sofia; Federico Batiz, Luis; Campisto, Yessica; Cepeda, Mariela; Cortes, Aaron; Lopez, Sofia; Loreto Perez, Maria; Schilling, Andrea; Kalergis, Alexis M.
    Several vaccines have been developed to control the COVID-19 pandemic. CoronaVac (R), an inactivated SARS-CoV-2 vaccine, has demonstrated safety and immunogenicity, preventing severe COVID-19 cases. We investigate the safety and non-inferiority of two immunization schedules of CoronaVac (R) in a non-inferiority trial in healthy adults. A total of 2302 healthy adults were enrolled at 8 centers in Chile and randomly assigned to two vaccination schedules, receiving two doses with either 14 or 28 days between each. The primary safety and efficacy endpoints were solicited adverse events (AEs) within 7 days of each dose, and comparing the number of cases of SARS-CoV-2 infection 14 days after the second dose between the schedules, respectively. The most frequent local AE was pain at the injection site, which was less frequent in participants aged >= 60 years. Other local AEs were reported in less than 5% of participants. The most frequent systemic AEs were headache, fatigue, and myalgia. Most AEs were mild and transient. There were no significant differences for local and systemic AEs between schedules. A total of 58 COVID-19 cases were confirmed, and all but 2 of them were mild. No differences were observed in the proportion of COVID-19 cases between schedules. CoronaVac (R) is safe, especially in >= 60-year-old participants. Both schedules protected against COVID-19 hospitalization.