Browsing by Autor "Antonieta Rojas de Árias"

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Chemical Composition and Insecticidal Activity ofHedeoma mandonianaEssential Oils
(Taylor & Francis, 2004) Antonio Vilaseca; Isabelle Guy; Brigitte Charles; Hélène Guinaudeau; Antonieta Rojas de Árias; Alain Fournet
Abstract The analysis by GC/MS of samples of essential oils obtained from aerial parts of Hedeoma mandoniana allowed the identification of 58 components. The main components were pulegone (37–46%), 1,8-cineole (10–14%), linalool (7–12%) and 1-octen-3-yl acetate (7–12%). We investigated the efficacy of these oils against the Chagas' insect disease vectors (Triatoma infestans Klug or Rhodnius neglectus Lent) bugs by topical application. Two samples showed a moderate activity (33.3% of mortality) on Rhodnius neglectus exemplars.
Isoenzyme profiles of Trypanosoma cruzi stocks from different areas of Paraguay
(Instituto Oswaldo Cruz, Ministério da Saúde, 2001) Nidia Acosta; Margarita Samudio; Elsa López; Fernando Regla Vargas; Nina Yaksic; Simone Frédérique Brénière; Antonieta Rojas de Árias
Twenty one Trypanosoma cruzi stocks from humans, domiciliary triatomines and one sylvatic animal of different areas of Paraguay were subjected to isoenzyme analysis. Thirteen enzyme systems (15 loci in total) were studied. MN cl2 (clonets 39) and SO34 cl4 (clonets 20) were used as references. Relationships between stocks were depicted by an UPGMA dendrogram constructed using the Jaccard's distances matrix. Among the Paraguayan stocks 14 zymodemes were identified (Par1 to Par14), Par 5 being the most frequent. Polymorphism rate and clonal diversity were 0.73 and 0.93, respectively. Average number of alleles per polymorphic locus was 2.5 (range 2-4). These measurements show a high diversity, which is confirmed by the dendrogram topology. All stocks belong to the same lineage, as MN cl2 reference strain (T. cruzi II). Moreover three distinct subgroups were identified and two of them correspond to Brazilian and Bolivian zymodemes, respectively. The third subgroup, the most common in Paraguay, is related to Tulahuen stock. The large geographical distribution of some zymodemes agrees with the hypothesis of clonality for T. cruzi populations. However sample size was not adequate to detect genetic recombination in any single locality.
Leishmanicidal and Trypanocidal activities of Acetogenins isolated fromAnnona glauca
(Wiley, 1998) Anne-Isabelle Waechter; Gloria Yaluff; Alba Inchausti; Antonieta Rojas de Árias; Reynald Hocquemiller; André Cavé; Alain Fournet
The dichloromethane extract of seeds of Annona glauca (Annonaceae) was active against three strains of Leishmania species. Nine known acetogenins were isolated and identified and then evaluated in vitro against Leishmania species and the bloodstream forms of Trypanosoma cruzi. Annonacin A and goniothalamicin showed activity against Leishmania, and glaucanisin, squamocin, annonacin A and annonacin against Trypanosoma cruzi reducing the parasites by 78%, 67%, 71% and 85%, respectively. Copyright © 1998 John Wiley & Sons, Ltd.
Phenotypic variability in traits related to flight dispersal in the wing dimorphic species Triatoma guasayana
(BioMed Central, 2023) Gisel V. Gigena; Claudia Rodríguez; Federico G. Fiad; María Laura Hernández; Ana Laura Carbajal-de-la-Fuente; Romina V. Piccinali; Paz Sánchez Casaccia; Antonieta Rojas de Árias; Patricia A. Lobbia; Luciana Abrahan
Scorpion Envenoming as an Emerging Public Health Problem in Paraguay, Bolivia, and Midwest Brazil: Involvement of Tityus confluens and the Need for a Panregional Evaluation of Available Antivenoms
(American Society of Tropical Medicine and Hygiene, 2024) Adolfo Borges; Antonieta Rojas de Árias; Ana María Montaño; Cláudio Maurício Vieira de Souza
This contribution highlights the emergence of a newly endemic region for scorpion envenoming in South America, covering eastern Bolivia, Paraguay, and the midwestern Brazilian states of Mato Grosso and Mato Grosso do Sul. These areas have not historically been known to harbor life-threatening scorpion species. Tityus confluens, a parthenogenetic species of medical significance in Argentina, has been identified in severe and lethal human cases in Bolivia and Paraguay. Given that the clinical use of scorpion antivenom preparations in the region has often lacked preclinical data and considering the significant burden of scorpion envenoming, we propose a panregional evaluation of available anti-Tityus antivenoms. This evaluation, along with interdisciplinary efforts at a multinational scale to control scorpionism, aims to determine their true neutralization capacity and potential clinical efficacy against known culprits in the Southern Cone of South America and other regions endemic for scorpion envenoming on the continent.
Wing geometry in Triatoma infestans (Klug) and T. melanosoma Martinez, Olmedo & Carcavallo (Hemiptera: Reduviidae)
(Wiley, 2003) Márcia Gumiel; S. Catalá; François Noireau; Antonieta Rojas de Árias; Alejandra García; Jean‐Pierre Dujardin
Abstract. Geometric morphometrics is a novel approach to biological shape analysis, and its application to medical entomology is just beginning. Here, we use it to examine geographical and interspecific variation in the Triatoma infestans complex, vectors of Chagas disease in southern Latin America. Using six landmarks defining the membranous part of the hemelytra, we analysed the geographical patterns of variation in several populations of T . infestans , including the recently described ‘dark morph’ of T . infestans from hollow trees in the Bolivian Chaco. As a potential outgroup, T. melanosoma was added to the sample. A consistent geographical differentiation was observed, but no evidence was found in either sex to consider either the dark morph or T. melanosoma as a species distinct from T. infestans . Triatoma melanosoma is relegated to synonymy with T. infestans (syn.n.).