Browsing by Author "Vidal, Marcela"
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- ItemCurrent threats faced by amphibian populations in the southern cone of South America(2022) Pablo Kacoliris, Federico; Berkunsky, Igor; Carlos Acosta, Juan; Acosta, Rodrigo; Gabriela Agostini, Maria; Sebastian Akmentins, Mauricio; Luz Arellano, Maria; Azat, Claudio; Carla Bach, Nadia; Mirta Blanco, Graciela; Calvo, Rodrigo; Charrier, Andres; Corbalan, Valeria; Correa, Claudio; Elena Cuello, Maria; Deutsch, Camila; Di-Pietro, Diego; Soledad Gaston, Maria; Gomez-Ales, Rodrigo; Kass, Camila; Kass, Nicolas; Lobos, Gabriel; Agustin Martinez, Tomas; Martinez-Aguirre, Tomas; Mora, Marta; Nieva-Cocilio, Rodrigo; Pastore, Hernan; Manuel Perez-Iglesias, Juan; Piaggio-Kokot, Lia; Rabanal, Felipe; Jesus Rodriguez-Munoz, Melina; Cecilia Sanchez, Laura; Tala, Charif; Ubeda, Carmen; Vaira, Marcos; Alicia Velasco, Melina; Vidal, Marcela; Daniel Williams, JorgeIn this work, we update and increase knowledge on the severity and extent of threats affecting 57 populations of 46 amphibian species from Chile and Argentina in southern South America. We analyzed the intrinsic conser-vation problems that directly impact these populations. We shared a questionnaire among specialists on threats affecting target amphibian populations with information on i) range, ii) historical occurrence and abundance, iii) population trends, iv) local extinctions, v) threats, and vi) ongoing and necessary conservation/research. We assessed association patterns between reported threats and population trends using multiple correspondence analysis. Since 2010, 25 of 57 populations have declined, while 16 experienced local extinctions. These pop-ulations were affected by 81% of the threat categories analyzed, with those related to agricultural activities and/ or habitat modifications being the most frequently reported. Invasive species, emerging diseases, and activities related to grazing, ranching, or farming were the threats most associated with population declines. Low con-nectivity was the most frequent intrinsic conservation problem affecting 68% of the target populations, followed by low population numbers, affecting 60%. Ongoing monitoring activity was conducted in 32 (56%) populations and was the most frequent research activity. Threat mitigation was reported in 27 (47%) populations and was the most frequent ongoing management activity. We found that habitat management is ongoing in 5 (9%) pop-ulations. At least 44% of the amphibian populations surveyed in Chile and Argentina are declining. More in-formation related to the effect of management actions to restore habitats, recover populations, and eliminate threats such as invasive species is urgently needed to reverse the conservation crisis facing amphibians in this Neotropical region.
- ItemNatural history of the Mocha Island ground frog Eupsophus insularis, a critically endangered species(2021) Lobos, Gabriel; Rebolledo, Nicolas; Charrier, Andres; Correa, Claudio; Rabanal, Felipe; Vidal, MarcelaEupsophus insularis inhabits a small island in the southeast Pacific, and its natural history is unknown. The species is listed as Critically Endangered based on its restricted distribution, i.e., an island under ongoing habitat deterioration. We assessed the distribution, habitat requirements, density, diet, and threats of the species with the aim of proposing strategies for its conservation. The species is restricted to a terrestrial strip 24-205 m above sea level associated with pristine temperate humid forests located in areas of low slope. A capture-recapture study indicated that its density was 15-66 individuals/ha of optimal habitat. Its diet is composed mainly of invertebrates of the humid forest floor. The high prevalence of chytrid fungus and habitat loss are important threats to the species. Herein, we present data to help with the management of the species on the island and that might help in designing more robust strategies to mitigate present and future threats.
- ItemRespuesta inmune humoral inducida por la vacuna influenza en niños con diagnóstico de leucemia linfoblástica aguda(Sociedad Chilena de Infectología, 2020) Cerda Valenzuela, Carolina Angélica; Martínez Valdebenito, Constanza Pamela; Barriga Cifuentes, Francisco José; Contreras, Marcela; Vidal, Marcela; Moreno, Rosa; Claverie, Ximena; Contreras, Paola; Huenuman, Lesly; García Salum, Tamara Cristal; Rathnasighe, Raveen; Medina Silva, Rafael Andrés; Ferrés Garrido, Marcela Viviana; Le Corre Pérez, Monique NicoleBackground: Patients with acute lymphoblastic leukemia (ALL) have high risk of severe influenza infection and vaccination is highly recommended. The immunogenicity and effectiveness of vaccination are lower than in healthy people. Aim: To evaluate the immune response induced by influenza vaccine in children with ALL and observe effectiveness. Method: Children with ALL in maintenance phase and healthy children were recruited. Blood samples were taken at vaccination day (D0) and at day 28 (D28). Humeral response was evaluated by hemaglutination inhibition test (HAI) against H1N1. Patients were followed up for one year, clinical data and influenza episodes were recorded. Results: 34 children with ALL and 9 healthy children were included. Concerning HAI on D28, 12/34 patients and 5/8 healthy children had titers >= 1/40, with seroprotection rates of 35 and 63% respectively. Seroprotected children were older than non-seroprotected ones. During follow-up, only 3 patients non seroprotected, presented influenza infection, without oxygen supplementation or critical care support. Discussion: Children with ALL had a lower seroprotection rate than healthy children. Nevertheless, none of the seroprotected children presented influenza infection, reinforcing the annual vaccination recommendation.
- ItemSteatotic livers. Can we use them in OLTX? Outcome data from a prospective baseline liver biopsy study(MEXICAN ASSOC HEPATOLOGY, 2012) Gabriel, Mauricio; Moisan, Fabrizio; Vidal, Marcela; Duarte, Ignacio; Jimenez, Macarena; Izquierdo, Guillermo; Dominguez, Pilar; Mendez, Javier; Soza, Alejandro; Benitez, Carlos; Perez, Rosa; Arrese, Marco; Guerra, Juan; Jarufe, Nicolas; Martinez, JorgeIntroduction. Steatotic livers have been associated with greater risk of allograft dysfunction in liver transplantation. Our aim was to determinate the prevalence of steatosis in grafts from deceased donors in Chile and to assess the utility of a protocol-bench biopsy as an outcome predictor of steatotic grafts in our transplant program. Material and methods. We prospectively performed protocol-bench graft biopsies from March 2004 to January 2009. Biopsies were analyzed and classified by two independent pathologists. Steatosis severity was graded as normal from absent to < 6%; grade 1: 6-33%; grade 2: > 33-66% and grade 3: > 66%. Results. We analyzed 58 liver grafts from deceased donors. Twenty-nine grafts (50%) were steatotic; 9 of them (16%) with grade 3. Donor age (p < 0.001) and BMI over 25 kg/m(2) (p = 0.012) were significantly associated with the presence of steatosis. There were two primary non-functions (PNF); both in a grade 3 steatotic graft. The 3-year overall survival was lower among recipients with macrovesicular steatotic graft (57%) than recipients with microvesicular (85%) or non-steatotic grafts (95%) (p = 0.026). Conclusion. Macrovesicular steatosis was associated with a poor outcome in this series. A protocol bench-biopsy would be useful to identify these grafts.