2,013 research outputs found

    Integrated control of chagas disease for its elimination as public health problem: A review

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    Chagas disease or American trypanosomiasis is, together with geohelminths, the neglected disease that causes more loss of years of healthy life due to disability in Latin America. Chagas disease, as determined by the factors and determinants, shows that different contexts require different actions, preventing new cases or reducing the burden of disease. Control strategies must combine two general courses of action including prevention of transmission to prevent the occurrence of new cases (these measures are cost effective), as well as opportune diagnosis and treatment of infected individuals in order to prevent the clinical evolution of the disease and to allow them to recuperate their health. All actions should be implemented as fully as possible and with an integrated way, to maximise the impact. Chagas disease cannot be eradicated due because of the demonstrated existence of infected wild triatomines in permanent contact with domestic cycles and it contributes to the occurrence of at least few new cases. However, it is possible to interrupt the transmission of Trypanosoma cruzi in a large territory and to eliminate Chagas disease as a public health problem with a dramatic reduction of burden of the disease.Fil: Sosa-Estani, Sergio Alejandro. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Segura, Elsa Leonor. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Energy Transfer in Ion– and Laser–Solid Interactions

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    La noción de predicción en matemáticas. Un análisis cualitativo transversal

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    En este artículo se discuten los procesos de construcción de conocimiento escolar relacionados con la noción de predicción matemática. Se evidencian condiciones socioculturales y acciones que favorecieron en jóvenes de distintos niveles educativos la movilización de recursos de construcción de conocimiento asociado al Cálculo, observadas en la experimentación de actividades predictivas de naturaleza variacional en escenarios numéricos y gráficos

    Woodification of polygonal meshes

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    An evolving polygonal mesh based on stem\u27s tree growth coupled with a physical simulation of bark\u27s cracking is presented. This process is denominated woodification. Whereas previous approaches use a fixed resolution voxel grid, woodification is built on the deformable simplicial complex representation, which robustly simulates growth with adaptive subdivision. The approach allows any meshed object to be grown and textured. Features, such as interaction with obstacles, attributes interpolation, and sketching tools, are added to provide control during the woodifible process

    Hybrid rendering of exploded views for medical image atlas visualization

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    Medical image atlases contain much information about human anatomy, but learning the shapes of anatomical regions and making sense of the overall structure defined in the atlas can be problematic. Atlases may contain hundreds of regions with complex shapes which can be tightly packed together. This makes visualisation difficult since the shapes can fit together in complex ways and visually obscure each other. In this work, we describe a technique which enables interactive exploration of medical image atlases that permits the hierarchical structure of the atlas and the content of an underlying medical image to be investigated simultaneously. Our method enables a user to create visualizations of the atlas similar to the exploded views used in technical illustrations to show the structure of mechanical assemblies. These views are constrained by the geometry of the atlas and the hierarchical structure to reduce the complexity of user interaction. We also enable the user to explode the atlas meshes themselves. The atlas meshes are registered with a medical image which is displayed on the cut surfaces of the meshes using raycasting. Results from the AAL human brain atlas are presented and discussed

    Electrocardiographic Abnormalities and Treatment with Benznidazole among Children with Chronic Infection by Trypanosoma cruzi: A Retrospective Cohort Study

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    Background: Chronic infection by Trypanosoma cruzi could cause heart conduction disturbances. We sought to analyze electrocardiographic abnormalities among children with chronic T. cruzi infection with and without trypanocidal treatment with benznidazole. Methodology/Principal Findings: We studied 111 children 6–16 years of age with asymptomatic chronic T. cruzi infection who were recruited in 1991–1992 in Salta, Argentina. Most children were randomly assigned to benznidazole 5 mg/Kg/day (n = 47) or matching placebo (n = 48) for 60 days. Remaining children (n = 16) received treatment with benznidazole 5 mg/Kg/day open-label. Electrocardiograms were obtained at baseline and in 1995–1996, 1998, 2000 and 2005, and were analyzed using the Buenos Aires method. Among the 94 children with an electrocardiogram at baseline, 8 (8.5%) had electrocardiographic abnormalities, including 4 (4.7%) children with right bundle branch block. Proportion of abnormal electrocardiograms in the full population (n = 111) remained constant over time (media follow-up 8.6 years). Multivariable adjusted prevalence ratios (95% confidence interval [95%CI]) for electrocardiographic abnormalities in 1995–1996, 1998, 2000 and 2005 comparing children treated with benznidazole versus those not treated were 2.76 (0.66, 11.60), 2.33 (0.44, 12.31), 3.06 (0.48, 19.56), and 1.94 (0.33, 11.25), respectively. Among the 86 children with a normal electrocardiogram at baseline, 16 (18.6%) developed electrocardiographic abnormalities during follow-up. The multivariable adjusted hazard ratio for incident electrocardiographic abnormalities comparing children treated with benznidazole versus those not treated was 0.68 (95%CI: 0.25, 1.88). Conclusions/Significance: Electrocardiographic abnormalities are frequent among children with chronic T. cruzi infection. Treatment with benznidazole for 60 days may not be associated with less electrocardiographic abnormalities.Fil: Colantonio, Lisandro Damián. University of Alabama at Birmingahm; Estados Unidos. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Prado, Nilda. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; ArgentinaFil: Segura, Elsa Leonor. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sosa-Estani, Sergio Alejandro. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Frequency of the Congenital Transmission of Trypanosoma cruzi: A Systematic Review and Meta-Analysis

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    BACKGROUND: Chagas disease is caused by the parasite Trypanosoma cruzi and is endemic in much of Latin America. With increased globalisation and immigration, it is a risk in any country, partly through congenital transmission. The frequency of congenital transmission is unclear. OBJECTIVE: To assess the frequency of congenital transmission of T. cruzi. SEARCH STRATEGY: PubMed, Journals@Ovid Full Text, EMBASE, CINAHL, Fuente Academica and BIREME databases were searched using seven search terms related to Chagas disease or T. cruzi and congenital transmission. SELECTION CRITERIA: The inclusion criteria were the following: Dutch, English, French, Portuguese or Spanish language; case report, case series or observational study; original data on congenital T. cruzi infection in humans; congenital infection rate reported or it could be derived. This systematic review included 13 case reports/series and 51 observational studies. DATA COLLECTION AND ANALYSIS: Two investigators independently collected data on study characteristics, diagnosis and congenital infection rate. The principal summary measure - the congenital transmission rate - is defined as the number of congenitally infected infants divided by the number of infants born to infected mothers. A random effects model was used. MAIN RESULTS: The pooled congenital transmission rate was 4.7% (95% confidence interval: 3.9-5.6%). Countries where T. cruzi is endemic had a higher rate of congenital transmission compared with countries where it is not endemic (5.0% versus 2.7%). CONCLUSIONS: Congenital transmission of Chagas disease is a global problem. Overall risk of congenital infection in infants born to infected mothers is about 5%. The congenital mode of transmission requires targeted screening to prevent future cases of Chagas disease.Fil: Howard, Elizabeth J.. University of Tulane; Estados UnidosFil: Xiong, Xu. University of Tulane; Estados UnidosFil: Carlier, Yves. Université Libre de Bruxelles; BélgicaFil: Sosa-estani, Sergio Alejandro. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Buekens, Pierre. University of Tulane; Estados Unido

    The burden of congenital Chagas disease and implementation of molecular diagnostic tools in Latin America

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    It is estimated that between 8000 and 15 000 Trypanosoma cruzi infected babies are born every year to infected mothers in Chagas disease endemic countries. Currently, poor access to and performance of the current diagnostic algorithm, based on microscopy at birth and serology at 8-12 months after delivery, is one of the barriers to congenital Chagas disease (CCD) control. Detection of parasite DNA using molecular diagnostic tools could be an alternative or complement to current diagnostic methods, but its implementation in endemic regions remains limited. Prompt diagnosis and treatment of CCD cases would have a positive clinical and epidemiological impact. In this paper, we analysed the burden of CCD in Latin America, and the potential use of molecular tests to improve access to early diagnosis and treatment of T. cruzi infected newborns.Fil: Picado, Albert. Foundation for Innovative New Diagnostics; SuizaFil: Cruz, Israel. Foundation for Innovative New Diagnostics; SuizaFil: Redard Jacot, Maël. Foundation for Innovative New Diagnostics; SuizaFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Torrico, Faustino. Universidad Mayor de San Simón; Bolivia. Fundación CEADES; BoliviaFil: Sosa-Estani, Sergio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentina. Drugs for Neglected Diseases initiative; BrasilFil: Katz, Zachary. Foundation for Innovative New Diagnostics; SuizaFil: Ndung'u, Joseph Mathu. Foundation for Innovative New Diagnostics; Suiz

    A new Neotropical species of Megamelus and the reassignment of Stenocranus maculipes (Hemiptera: Delphacidae)

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    Se estudian dos especies de Delphacidae que habitan en humedales de la Argentina, Megamelus nigrifasciatus Mariani & Remes Lenicov sp. nov. y Megamelus maculipes (Berg) comb. nov. La primera fue colectada sobre Eryngium sp. (Apiales: Apiaceae) y se describe a partir de formas braquípteras de ambos sexos. Además, se propone a Stenocranus maculipes (Berg, 1879), colectada en Echinodorus grandiflorum (Alismataceae), como Megamelus maculipes comb. nov. Se redescribe el holotipo hembra macróptero y se describen por primera vez los braquípteros de ambos sexos. Se aportan datos distribucionales y biológicos de las especies tratadas y se menciona por primera vez al género Eryngium como hospedante del género Megamelus. Asimismo, se provee una clave para la identificación de las siete especies sudamericanas de Megamelus.We report on two species of Delphacidae from Argentine wetlands, Megamelus nigrifasciatus Mariani & Remes Lenicov sp. nov. and Megamelus maculipes (Berg) comb. nov. The first species was collected from Eryngium sp. (Apiales: Apiaceae) and was described from the brachypters of both sexes. The second one, Stenocranus maculipes (Berg, 1879) collected from Echinodorus grandiflorum (Alismataceae), is proposed as Megamelus maculipes comb.nov. The female macropter holotype is redescribed and the male and female brachypters are described for the first time. Geographic distribution and biological data of both species are reported. The genus Eryngium is cited for the first time as host plant for the genus Megamelus. Additionally, a key is provided to distinguish among the seven South American species of Megamelus.Fil: Mariani, Roxana. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico La Plata; ArgentinaFil: Sosa, Alejandro Joaquín. Fundación para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marino, Ana Maria. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico La Plata; Argentin
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