Resumo O rio Cautín está intimamente relacionado ao desenvolvimento econômico da cidade de Temuco (38°S; Chile). Quanto ao conhecimento total do rio Cautín, existem informações limitadas sobre as características biológicas que podem servir de referência para a avaliação da qualidade da água. Este estudo tem o objetivo de caracterizar os macroinvertebrados bentônicos taxonomicamente ao longo do curso principal do rio Cautín e estudar a estrutura da comunidade usando análise de correlação entre os parâmetros dela. Para realizar esta pesquisa, a comunidade de macroinvertebrados foi estudada em dez locais de estudo distribuídos ao longo do rio principal. As amostras foram coletadas no verão (1997 e 2000), em razão das condições hidrológicas ideais. A análise das amostras mostrou que a fauna bentônica é composta de 56 táxons, sendo o grupo dominante o de insetos com 48 táxons. Na distribuição do principal no curso do rio, três setores são reconhecidos: alto, médio e baixo no rio Cautín. Cada setor possui espécies de distribuição restrita e outro com ampla distribuição ao longo do rio. Esses padrões de distribuição parecem influenciar a concentração de oxigênio dissolvido, a temperatura, a distribuição altitudinal e a atividade antropocultural desenvolvida em todos os locais de amostragem. Finalmente, esta pesquisa fornece uma primeira abordagem biológica do rio Cautín e, de acordo com esses conhecimentos, um estudo posterior pode ser planejado em relação aos indicadores de qualidade da água e com base nas comunidades de macroinvertebrados.

Abstract The Cautín River is closely related with the economic development of Temuco city, (38°S; Chile). Existing knowledge of the Cautín River is limited to information about its biological characteristics as a reference for the evaluation and assessment of water quality. The object of this study was to develop taxonomic characterisation of the benthic macroinvertebrates along the main course of the Cautín River, and to study the community structure using correlation analysis between community parameters. To carry out this research, the macroinvertebrate community was studied in 10 sampling sites distributed along the main course of the river. The samples were taken in summer (1997 and 2000), when optimal hydrological conditions existed. Analysis of the samples showed that the benthic fauna was composed of 56 taxa, the dominant group being insects with 48 taxa. Three main sectors were recognised in the course of the Cautín River: high, middle and low. Each sector has restricted-distribution species, while other species are widely distributed along the river. These distribution patterns seem to be influenced by dissolved oxygen concentration, temperature, altitudinal distribution and anthropo-cultural activity, present at every sampling site. Finally, this research provides a first approach to the biology of the Cautín River. Further studies could be planned on the basis of this knowledge to investigate water quality indicators based on macroinvertebrate communities.

Abstract The nutritional status of a plant can be negatively modified by toxic elements that have an analogy with essential nutrients or by the stress caused at the absorption sites. The absorption and distribution of nutrients in roots and leaves of tomato plants (Solanum lycopersicum L.) developed under conditions of contamination by arsenic in the nutrient solution and treated with nanoparticles of silicon dioxide was evaluated. The plants were grown for 150 days in greenhouse conditions and soilless culture. Different concentrations of arsenate (0, 0.2, 0.4, 0.8, 1.6 and 3.2 mg L-1) were applied through the nutritive solution, and three concentrations of nanoparticles of silicon dioxide (0, 250 and 1000 mg L-1) applied via drench. The dry root and shoot biomass production was determined, as well as the concentration of micronutrients (Fe, Cu, Zn) and macronutrients (K, S, P) in roots and leaves. Exposure to arsenic in low doses resulted in there is a slight stimulation of the dry biomass. The application of only nanoparticles of silicon dioxide also significantly reduced biomass. The presence of arsenic in the nutrient solution decreased the uptake of Fe, Cu, Zn and P in roots, but increased the uptake of K. The nanoparticles of silicon dioxide increased the uptake of macronutrients in roots and leaves. The uptake of nutrients by tomato plants is negatively affected by the presence of arsenic in the nutritive solution, however, this effect can be reversed with the application of nanoparticles of silicon dioxide since it favors the uptake of nutrients.

Resumen El estado nutricional de una planta puede verse modificado negativamente por elementos tóxicos que tienen una analogía con los nutrientes esenciales, o por el estrés causado en los sitios de absorción. Se evaluó la absorción y distribución de nutrientes en raíces y hojas de plantas de tomate (Solanum lycopersicum L.) desarrolladas en condiciones de contaminación por arsénico en la solución nutritiva y tratadas con nanopartículas de dióxido de silicio. Las plantas se cultivaron durante 150 días en condiciones de invernadero en cultivo sin suelo. Se aplicaron diferentes concentraciones de arseniato (0, 0.2, 0.4, 0.8, 1.6 y 3.2 mg L-1) a través de la solución nutritiva, y se aplicaron tres concentraciones de nanopartículas de dióxido de silicio (0, 250 y 1000 mg L-1) vía suelo. Se determinó la producción de biomasa seca de raíces y parte aérea, así como la concentración de micronutrientes (Fe, Cu, Zn) y macronutrientes (K, S, P) en raíces y hojas. La exposición al arsénico en dosis bajas resultó en una leve estimulación de la biomasa seca. La aplicación de sólo nanopartículas de dióxido de silicio también redujo significativamente la biomasa. La presencia de arsénico en la solución nutritiva disminuyó la absorción de Fe, Cu, Zn y P en las raíces, pero aumentó la absorción de K. Las nanopartículas de dióxido de silicio aumentaron la absorción de macronutrientes en raíces y hojas. La absorción de nutrientes por las plantas de tomate se ve afectada negativamente por la presencia de arsénico en la solución nutritiva, sin embargo, este efecto puede revertirse con la aplicación de nanopartículas de dióxido de silicio ya que favorece la absorción de nutrientes.

ABSTRACT Introduction: The World Health Organization has recently reported that the new focus of the global pandemic of Covid-19 disease is the American continent. Objective: To conduct a literature review on the international experience of the Covid 19 pandemic and pregnancy. Method: A PubMed database search is performed for the keywords Pregnancy / Pregnant / Novel Coronavirus / SARS-CoV-2 / Covid-19, from November 1, 2019 to May 21, 2020. Results: A total of 365 articles were initially selected according to the designed search strategy. The total of articles reviewed according to the criteria was 42. The selected clinical series accumulated a total of 1098 pregnant women and Covid-19 disease. The most frequent comorbidities were hypertension, diabetes mellitus, obesity, and asthma. Mortality in relation to the total number of patients was 1.2% and transmission to the newborn was 1.7% (15 of 875). Conclusion: The information obtained allows us to infer that the clinical presentation of the disease is at least equivalent to that of non-pregnant women of the same age. Given the severity of the reported SARS-CoV-2 disease, the lessons learned must be quickly assimilated and used in the context of the national epidemic situation.

RESUMEN Introducción: La Organización Mundial de La Salud ha reportado recientemente que el nuevo foco de la pandemia global de la enfermedad Covid-19 es el continente americano. Objetivo: Realizar una revisión de la literatura sobre la experiencia internacional de la pandemia Covid 19 y embarazo. Método: Se realiza una búsqueda de la base de datos PubMed para las palabras clave Pregnancy / Pregnant / Novel Coronavirus / SARS-CoV-2 / Covid-19, desde el 1 de noviembre 2019 hasta el 21 de mayo 2020. Resultados: Un total de 365 artículos fueron inicialmente seleccionados de acuerdo con la estrategia de búsqueda diseñada. El total de artículos revisados de acuerdo con los criterios fueron 42. Las series clínicas seleccionadas acumularon un total de 1098 embarazadas y enfermedad de Covid-19. Las co-morbilidades mas frecuentes fueron hipertensión arterial, diabetes mellitus, obesidad y asma. La mortalidad en relación con el total de pacientes fue de un 1,2 % y la transmisión al recién nacido de 1,7% (15 de 875). Conclusión: La información obtenida permite inferir que la presentación clínica de la enfermedad es a lo menos equivalente a la de mujeres de la misma edad no embarazadas. Dada la severidad de la enfermedad por SARS-CoV-2 reportada, las lecciones aprendidas deben ser rápidamente asimiladas y utilizadas en el contexto de la situación nacional epidémica.

Multiple pregnancies are considered a high-risk obstetric entity. Their incidence has been increasing due to the use of assisted reproductive techniques and increased maternal age. Here, we describe two cases of triamniotic monochorionic triplet pregnancies, female and male respectively. Both pregnancies demonstrated complications, mainly fetal and neonatal, attributed to multiple pregnancies reported in the literature.

Los embarazos múltiples se consideran una entidad de alto riesgo obstétrico. Su incidencia ha ido en aumento debido a la utilización de técnicas de reproducción asistida y el aumento de la edad materna. Se presentan 2 casos de embarazos triples monocoriales triamnióticos, de sexo femenino y masculino. En ambos embarazos se manifestaron complicaciones, principalmente fetales y neonatales, atribuidas a embarazos múltiples descritas en la literatura.

The objective of the present study was to identify metabolic, cardiovascular and autonomic changes induced by fructose overload administered in the drinking water of rats for 8 weeks. Female Wistar rats (200-220 g) were divided into 2 groups: control (N = 8) and fructose-fed rats (N = 5; 100 mg/L fructose in drinking water for 8 weeks). The autonomic control of heart rate was evaluated by pharmacological blockade using atropine (3 mg/kg) and propranolol (4 mg/kg). The animals were submitted to an intravenous insulin tolerance test (ITT) and to blood glucose measurement. The fructose overload induced a significant increase in body weight (~10%) and in fasting glycemia (~28%). The rate constant of glucose disappearance (KITT) during ITT was lower in fructose-fed rats (3.25 ± 0.7%/min) compared with controls (4.95 ± 0.3%/min, P < 0.05) indicating insulin resistance. The fructose-fed group presented increased arterial pressure compared to controls (122 ± 3 vs 108 ± 1 mmHg, P < 0.05) and a reduction in vagal tonus (31 ± 9 vs 55 ± 5 bpm in controls, P < 0.05). No changes in sympathetic tonus were observed. A positive correlation, tested by the Pearson correlation, was demonstrable between cardiac vagal tonus and KITT (r = 0.8, P = 0.02). These data provided new information regarding the role of parasympathetic dysfunction associated with insulin resistance in the development of early metabolic and cardiovascular alterations induced by a high fructose diet.

Objective: To valídate the use of cell free fetal DNA (ffDNA) in maternal plasma to predict fetal sex in the first half of pregnancy. Method: A prospective observational cohort study of 25 pregnancies between 5 and 15 weeks of gestation was studied (median gestational age of 9+1 weeks). Maternal blood was taken and q-PCR was carried out to detect the multi-copy Y chromosome associated DSY14 gene. The end point was gender as assessed by ultrasound at 20-25 weeks. Results: A Y signal was obtained in 12 patients, so a male fetus was predicted. The earliest signal was at 6+4 weeks. In 9 patients we didn't have any signal, so a female fetus was diagnosed. There were 4 cases where the criterion to define fetal sex was not fulfilled and were classified as equivocal (all of them before 8+3 weeks). The probability to predict fetal sex from the test was 84% (21 of 25 patients). However, when the diagnosis of fetal sex is made, there is a 100% correlation between the ultrasound and Q-PCR. Conclusión: Free fetal DNA in maternal plasma allows prediction of fetal sex in the first half of pregnancy

Objetivo: Establecer la validez diagnóstica de la identificación del sexo fetal en plasma de mujeres embarazadas durante la primera mitad del embarazo mediante medición de ADN libre fetal (ffDNA) en sangre materna. Método: Se extrajo 20 mi de sangre periférica a 25 pacientes entre las 5 y 15 semanas de gestación, previo consentimiento informado. Se separó el plasma mediante centrifugación obteniéndose ADN genómi-co total (materno y fetal), y se analizó por triplicado mediante PCR en tiempo real (q-PCR), con partidores específicos para secuencia del cromosoma Y (DYS14). El sexo fetal se confirmó mediante ecografía realizada entre las 20 y 25 semanas. Resultados: 12 pacientes presentaron amplificación para DYS14, siendo diagnosticados como fetos masculinos. La menor edad gestacional de diagnóstico fue 6+4 semanas. En 9 pacientes no se generó señal, estableciéndose el sexo fetal como femenino. Hubo 4 casos en donde no se cumplieron los criterios para definir el sexo fetal, estableciéndose estos como indeterminados (todos ellos antes de las 8+3 semanas). La probabilidad de diagnosticar el sexo a partir del test fue de 84% (21 de 25 pacientes). Considerando solo los 21 casos donde se pudo realizar un diagnóstico, la ecografía confirmó el sexo en todos ellos, obteniéndose una correlación del 100%. Conclusión: Es posible diagnosticar el sexo fetal en sangre materna utilizando ffDNA durante la primera mitad del embarazo

Hematological parameters of birds and mammals seem to respond to environmental requirements, such as hypoxia at high altitude and the energetic demands of locomotion and flight. In this work we hypothesize that lung capillary hematocrit and red blood size may be influenced by the energetic requirements of flight. Also, we propose that hematological parameters should vary together with the morphological parameters that determine oxygen diffusion capacity. We analyzed the red blood cell size and the local characteristics of the pulmonary capillary hematocrit correlating these with the pulmonary factors that determines the oxygen diffusion capacity. We deal with seven species, non-flying and flying birds and mammals, with different energetic requirements. The capillary hematocrit was not different in each taxon, but the red blood cell size was smaller in flying mammals and birds than non-flying ones. Correlation of erythrocyte size with the diffusing characteristics of the lungs produced a non-phylogenetic clustering with a group constituting by the bats Tadarida brasiliensis y Myotis chiloensis, and the bird Z. auriculata; revealing similar functional response in unrelated species. Finally, in mammals, a negative correlation between the red blood cell size and the mass-specific oxygen diffusion capacity was obtained. These results suggest that the direction of the hematological and pulmonary adjustments is governed mainly by the requirements of flight independent of phylogenetic origin of the species studied

Los parámetros hematológicos y pulmonares parecen responder a las exigencias ambientales como la hipoxia y la alta altitud y a los requerimientos energéticos de la locomoción. En este trabajo sometemos a prueba la hipótesis que el hematocrito del capilar pulmonar y el tamaño del glóbulo rojo pueden ser influidos por los requerimientos energéticos del vuelo. También proponemos que los parámetros hematológicos varían en conjunto con los parámetros que determinan la capacidad de difusión de oxígeno. Analizamos el tamaño del glóbulo rojo y las características locales del hematocrito capilar pulmonar correlacionándolos con los factores pulmonares que afectan la capacidad de difusión de oxígeno. Analizamos siete especies de diferente requerimiento energético, corredoras y voladoras. El hematocrito capilar pulmonar no mostró diferencias significativas en aves ni en mamíferos. El tamaño del glóbulo rojo fue menor en los mamíferos y en aves voladoras con respecto a sus pares no voladores. La respuesta conjunta del glóbulo rojo, la superficie respiratoria y la membrana alvéolo-capilar mostró un agrupamiento no filogenético donde se destaca un cluster constituido por mamíferos y aves de vuelo activo (dos murciélagos: Tadarida brasiliensis y Myotis chiloensis y la tórtola Zenaida auriculata). Finalmente, en mamíferos se obtiene una relación inversa entre la capacidad de difusión de oxígeno y el tamaño del glóbulo rojo. En definitiva, los hallazgos sugieren la existencia de ajustes funcionales hematológicos y pulmonares como una respuesta conjunta a las exigencias del vuelo, independientes de su origen filogenético

Uterine contractility can be measured quantitatively in vitro by the isometric method. The aim of the present work was to asses if insulin could modify uterotonic effect of oxytocyn. The uterine response to oxytocin alone and in the presence of insulin was studied in two different groups of rats: normal rats in different estral periods and pregnant rats at the end of pregnancy. The uterus of each group were compared in parallel bathing solutions with accumulative doses of oxytocin (10-10 M a 10-8 M) with or without insulin (200 mU/ml). As shown in the results, insulin was not able to modify oxytocin responses. However, under the same experimental conditions, insulin increased potassium uptake by the myometrium, as measured as Na-K ATPasa activity ouabain sensible. The last finding is an indication of the effectiveness of the hormone in the uterus; also, it is the first time that is shown that insulin behaves in the myometrium as shown previosly for skeletal muscle. The effect of insulin on the sodium pump is a further evidence that insulin has not a synergistic effect on the oxytocic responses.

La capacidad contráctil del útero puede ser evaluada in vitro por medio del método isométrico. El objetivo de este estudio fue comparar la efectividad de la administración simultánea de oxitocina e insulina en la contractilidad uterina. La comparación entre ambas hormonas se realizó en úteros aislados de dos modelos experimentales: ratas hembras adultas en diferentes fases del ciclo estral y ratas preñadas en fase final de preñez. Los úteros de estos animales fueron sometidos, in vitro, a la acción de dosis acumulativas de oxitocina (10-10 M a 10-8 M), insulina (200 mU/ml), y oxitocina más insulina. Los resultados obtenidos indican que in vitro la insulina no modificó significativamente la respuesta oxitócica. Sin embargo, la insulina aumentó la entrada de potasio al miometrio, medida como actividad de la Na-K ATPasa sensible a ouabaína. Este hallazgo indica efectividad de la insulina en el tejido uterino. Además es la primera demostración que insulina actúa en el miometrio en forma similar a lo descrito para el músculo esquelético. El efecto de insulina sobre la bomba de sodio indicaría que insulina no actuaría sinérgicamente con oxitocina.