Bioacumulación de cianotoxinas en ecosistemas dulceacuícolas en América Latina: una revisión

Background: The increasing evidence of risk to the environment and human health by cyanotoxin exposure during cyanobacterial blooms has been reported worldwide. Despite the knowledge of cyanotoxin presence in Latin America, cyanotoxin bioaccumulation from freshwater environments have not been reviewed for the region. Goals: To review the current knowledge of cyanotoxin accumulation in tissues of freshwater organisms in field studies in Latin America. Methods: An extensive literature search was conducted to construct a database including information on accumulation of cyanotoxins in organisms inhabiting freshwater environments in Latin America (i.e., México to Argentina). Results: We found twenty-one studies from 2001 to 2020, including twenty-seven mostly eutrophic water bodies, the majority from Brazil. Microcystis was the most reported genus responsible for cyanotoxin production. Fish comprised most of the species accumulating cyanotoxins (20 species). Nile tilapia (Oreochromis niloticus) was the most studied species, and 80% of the fish species included have commercial importance, which highlights a potential route of exposure to humans by consumption of contaminated food. Some studies showed the reduction of cyanotoxins in tissues after an experimental depuration time. Also, calculations of the potential human intakes of microcystins by fish consumption exceeded the recommendations of tolerable intakes in most of the cases. Conclusions: In Latin America, the geographic extent of studies is narrow, however the summarized information indicates a risk for environment and human health by cyanotoxins bioaccumulation. There is a need for more efforts to generate scientific research on cyanotoxins bioaccumulation, but also for improvement of local level management policies to reduce eutrophication.Antecedentes: La creciente evidencia de riesgo para el medio ambiente y la salud humana por la exposición a cianotoxinas durante las floraciones de cianobacterias se ha reportado en todo el mundo. A pesar del conocimiento de la presencia de cianotoxinas en América Latina, la bioacumulación de cianotoxinas en ambientes de agua dulce no ha sido revisada para la región. Objetivos: Revisar el conocimiento actual sobre la acumulación de cianotoxinas en tejidos de organismos de agua dulce en estudios de campo en América Latina. Métodos: Se realizó una extensa búsqueda bibliográfica para construir una base de datos que incluyera información sobre la acumulación de cianotoxinas en organismos que habitan ambientes de agua dulce en América Latina (de México a Argentina). Resultados: Encontramos veintiún estudios de 2001 a 2020, incluidos veintisiete cuerpos de agua en su mayoría eutróficos, la mayoría de Brasil. Microcystis fue el género productor de cianotoxinas más reportado. Los peces comprendieron la mayoría de las especies que acumulaban cianotoxinas (20 especies). Oreochromis niloticus fue la especie más estudiada, y el 80% de las especies de peces incluidas tienen importancia comercial, lo que destaca una vía potencial de exposición a los humanos. Algunos estudios demostraron la reducción de cianotoxinas en los tejidos después de un tiempo de depuración experimental. Además, los cálculos de las ingestas humanas potenciales de microcistinas por consumo de pescado excedieron las recomendaciones de ingestas tolerables en la mayoría de los casos. Conclusiones: En América Latina, los estudios se han realizado en pocos países, sin embargo, estos trabajos indican un riesgo para el medio ambiente y la salud humana por la bioacumulación de cianotoxinas. Se necesita más investigación científica sobre la bioacumulación de cianotoxinas, pero también esfuerzos para mejorar la gestión a nivel local con la finalidad de reducir la eutrofización

Research on classroom practice: A monograph for topic study group 24, ICME 11 - The introductory chapter

published_or_final_versionThe 11th International Congress on Mathematical Education (ICME 11), Monterrey, Mexico, 6-13 July 2008. In Quaderni di Ricerca in Didattica, 2009, n. S4, p. 1-

La importancia ecológica de las algas en los ríos

After reviewing several studies, we set out a proposal regarding the structure and function of benthic algae in rivers. We use an approach that considers the ecology of communities, the role of benthic algae in the rivers autochthonous primary productivity and their eco-physiology in the biogeochemical cycles of the water, their energy intake in food webs, the role they play in the hydrological dynamics in lotic environments, and their use as biological indicators. Finally, pharmaceutical and food industry use of the species in these environments is reviewed.A través de una revisión de diversos estudios, se realiza un planteamiento de la estructura y función que tienen las algas bentónicas en los ríos, desde un punto de vista de la ecología de comunidades, la participación que tienen en la productividad primaria autóctona de los ríos y su ecofisiología, en los ciclos biogeoquímicos del agua, su aporte energético en las redes tróficas, la función que tienen en la dinámica hídrica de los ambientes lóticos, su uso como indicadores biológicos y se plantean algunos usos que se han realizado con especies de estos ambientes en la industria farmaceútica y alimenticia

Limitations for pineapple production and commercialization and international research towards solutions

Pineapples are grown in more than 80 countries in tropical and subtropical regions. The global volume reached 25.44 million t in 2014 (FAO, 2014), ranking pineapple among the most important fruits. About 81% of that amount was produced in Asia and Latin America, where the leading countries of Costa Rica, Brazil, Philippines, Thailand and Indonesia are located. In spite of their similar large production volumes, there are significant differences among these countries in technological levels of crop and postharvest management and in the fruit markets targeted. Even within large countries like Brazil there are great variations in these aspects due to contrasts in regional environmental conditions and social factors representing strong challenges to be addressed by growers and traders. Costa Rica and Indonesia, among the big producers, are examples of pineapple industries with high technological input and outcome mostly focused on international markets. Australia, a smaller producer, has a similar input level, but fruits are directed to the inland market. On the other side, there are many countries, such as Brazil, where pineapples are mostly produced by small-holders using low inputs and their production is directed to national markets. And there are other countries in an intermediate position, such as Mexico and South Africa, with important volumes placed both into national and international markets. This work will give information on main challenges for pineapple production and commercialization in Australia, Brazil, Mexico, South Africa and some African countries with French background and make an analysis on research contributions to mitigate some of these challenges

Association between periodontal disease and endothelial dysfunction assessed by flow-mediated dilation in the brachial artery. Pilot study

Objetivo evaluar la disfunción endotelial a través de la vasodilatación mediada por flujo (VMF) en la arteria braquial en pacientes fumadores con periodontitis crónica avanzada y compararla con pacientes fumadores sin enfermedad periodontal, para determinar si hay diferencias en cuando a disfunción endotelial entre quienes presentan o no periodontitis crónica avanzada. Método se incluyeron 30 pacientes con hábito de tabaquismo, 15 con periodontitis crónica avanzada y 15 sin periodontitis. Se realizó historia clínica completa, exámenes de laboratorio y prueba de vasodilatación mediada por flujo de la arteria braquial. Resultados el estudio mostró que había diferencias significativas en los diámetros finales, resultantes de vasodilatación mediada por flujo (p=0,0328), con menores valores finales para quienes tenían enfermedad periodontal. Las diferencias en las respuestas porcentuales y en el número de personas con disfunción determinada dicotómicamente, no alcanzaron significación estadística. Conclusiones se observó que el grupo de pacientes con periodontitis crónica avanzada tuvo diámetros resultantes luego de la prueba que fueron significativamente menores que los del grupo de controles. Aunque al evaluar las diferencias en porcentajes no se alcanzó significación estadística, el estudio mostró una respuesta claramente menor en vasodilatación en el grupo con enfermedad periodontal.Q312-20Objective To evaluate endothelial dysfunction through flow-mediated vasodilation (FMD) in the brachial artery in smokers with advanced chronic periodontitis and compare it with smokers without periodontal disease, to determine whether there are differences in endothelial dysfunction among those with or without advanced chronic periodontitis. Method We included 30 patients with smoking habit, 15 with advanced chronic periodontitis and 15 without periodontal disease. We performed a complete medical history, laboratory tests and flowmediated vasodilation test of the brachial artery. Results The study showed that there were significant differences in the final diameters, resulting from flow-mediated dilation (p = 0.0328), with lower final values for those with periodontal disease. The differences in the percentage responses and the number of people with specific dysfunction determined dichotomously did not reach statistical significance. Conclusions We observed that the group of patients with advanced chronic periodontitis had after the test resulting diameters that were significantly lower than those in the control group. Although when evaluating differences in percentages no statistical significance was found, the study showed a clearly lower response in vasodilation in the group with periodontal disease

Twenty-year follow-up of kangaroo mother care versus traditional care

BACKGROUND AND OBJECTIVES: Kangaroo mother care (KMC) is a multifaceted intervention for preterm and low birth weight infants and their parents. Short- and mid-term benefits of KMC on survival, neurodevelopment, breastfeeding, and the quality of mother-infant bonding were documented in a randomized controlled trial (RCT) conducted in Colombia from 1993 to 1996. The aim of the present study was to evaluate the persistence of these results in young adulthood. METHODS: From 2012 to 2014, a total of 494 (69%) of the 716 participants of the original RCT known to be alive were identified; 441 (62% of the participants in the original RCT) were re-enrolled, and results for the 264 participants weighing less than 1800 g at birth were analyzed. The KMC and control groups were compared for health status and neurologic, cognitive, and social functioning with the use of neuroimaging, neurophysiological, and behavioral tests. RESULTS: The effects of KMC at 1 year on IQ and home environment were still present 20 years later in the most fragile individuals, and KMC parents were more protective and nurturing, reflected by reduced school absenteeism and reduced hyperactivity, aggressiveness, externalization, and socio-deviant conduct of young adults. Neuroimaging showed larger volume of the left caudate nucleus in the KMC group. CONCLUSIONS: This study indicates that KMC had significant, long-lasting social and behavioral protective effects 20 years after the intervention. Coverage with this efficient and scientifically based health care intervention should be extended to the 18 million infants born each year who are candidates for the method. Copyright © 2017 by the American Academy of Pediatrics

Asociación entre enfermedad periodontal y disfunción endotelial valorada por vasodilatación mediada por flujo en la arteria braquial. Estudio piloto

evaluar la disfunción endotelial a través de la vasodilatación mediada por flujo (VMF) en la arteria braquial en pacientes fumadores con periodontitis crónica avanzada y compararla con pacientes fumadores sin enfermedad periodontal, para determinar si hay diferencias en cuando a disfunción endotelial entre quienes presentan o no periodontitis crónica avanzada. Método: se incluyeron 30 pacientes con hábito de tabaquismo, 15 con periodontitis crónica avanzada y 15 sin periodontitis. Se realizó historia clínica completa, exámenes de laboratorio y prueba de vasodilatación mediada por flujo de la arteria braquial. Resultados: el estudio mostró que había diferencias significativas en los diámetros finales, resultantes de vasodilatación mediada por flujo (p=0,0328), con menores valores finales para quienes tenían enfermedad periodontal. Las diferencias en las respuestas porcentuales y en el número de personas con disfunción determinada dicotómicamente, no alcanzaron significación estadística. Conclusiones: se observó que el grupo de pacientes con periodontitis crónica avanzada tuvo diámetros resultantes luego de la prueba que fueron significativamente menores que los del grupo de controles. Aunque al evaluar las diferencias en porcentajes no se alcanzó significación estadística, el estudio mostró una respuesta claramente menor en vasodilatación en el grupo con enfermedad periodontal. Palabras clave: factores de riesgo, factores de riesgo cardiovascular, endotelio, fumar, enfermedad cardiovascular, vasodilatación, investigación

Preeclampsia: from epidemiological observations to molecular mechanisms.

Preeclampsia is the main cause of maternal mortality and is associated with a five-fold increase in perinatal mortality in developing countries. In spite of this, the etiology of preeclampsia is unknown. The present article analyzes the contradictory results of the use of calcium supplementation in the prevention of preeclampsia, and tries to give an explanation of these results. The proposal of an integrative model to explain the clinical manifestations of preeclampsia is discussed. In this proposal we suggest that preeclampsia is caused by nutritional, environmental and genetic factors that lead to the creation of an imbalance between the free radicals nitric oxide, superoxide and peroxynitrate in the vascular endothelium. The adequate interpretation of this model would allow us to understand that the best way of preventing preeclampsia is the establishment of an adequate prenatal control system involving adequate antioxidant vitamin and mineral supplementation, adequate diagnosis and early treatment of asymptomatic urinary and vaginal infections. The role of infection in the genesis of preeclampsia needs to be studied in depth because it may involve a fundamental change in the prevention and treatment of preeclampsia