Antioxidant and Antifungal Activities and Characterization of Phenolic Compounds Using High-Performance Liquid Chromatography and Mass Spectrometry (HPLC-MS) in Empetrum rubrum Vahl ex Willd.

In searching for compounds with antioxidant and antifungal activity, our study focused on the subshrub species Empetrum rubrum Vahl ex Willd. (Ericaceae). We measured the antioxidant activity of its methanolic extract (MEE) obtained from the aerial parts (leaves and stems) and of its methanolic extract (MEF) obtained from the lyophilized fruits. The antioxidant activity of the MEE and MEF was evaluated in vitro via a 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical and 2,2'-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) cationic radical. The results were expressed in gallic acid and Trolox equivalents for the DPPH and ABTS assays, respectively. The antioxidant activities, for the DPPH and ABTS assays, were also evaluated by considering the IC50 values. Concerning the antioxidant activity, the total phenolic content (TPC) in the MEE and MEF was determined using the Folin-Ciocalteu method. Polyphenols contained in the leaves, stems, and fruits of E. rubrum were determined qualitatively by employing high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) analysis. The antifungal activity of the MEE obtained from the aerial parts of E. rubrum was tested against Rhizoctonia solani. The results of IC50 values measured by the DPPH and ABTS methods with MEE were 0.4145 ± 0.0068 mg mL-1 and 0.1088 ± 0.0023 mg mL-1, respectively, and the IC50 values for MEF were 6.4768 ± 0.0218 mg mL-1 and 0.7666 ± 0.0089 mg mL-1 measured by the DPPH and ABTS methods, respectively. The HPLC-MS analysis revealed the presence of anthocyanins, phenolic acids derivatives, and flavonols. In vitro, mycelial growth of this fungus was reduced from 90% to nearly 100% in the presence of MEE. The observed antifungal effect is related to the presence of the abovementioned phenols, detected in the MEE.

Metabolome expression in Eucryphia cordifolia populations: Role of seasonality and ecological niche centrality hypothesis.

The ecological niche centrality hypothesis states that population abundance is determined by the position in the ecological niche, expecting higher abundances towards the center of the niche and lower at the periphery. However, the variations in the conditions that favor the persistence of populations between the center and the periphery of the niche can be a surrogate of stress factors that are reflected in the production of metabolites in plants. In this study we tested if metabolomic similarity and diversity in populations of the tree species Eucryphia cordifolia Cav. vary according to their position with respect to the structure of the ecological niche. We hypothesize that populations growing near the centroid should exhibit lower metabolites diversity than plants growing at the periphery of the niche. The ecological niche of the species was modeled using correlative approaches and bioclimatic variables to define central and peripheral localities from which we chose four populations to obtain their metabolomic information using UHPLC-DAD-QTOF-MS. We observed that populations farther away from the centroid tend to have higher metabolome diversity, thus supporting our expectation of the niche centrality hypothesis. Nonetheless, the Shannon index showed a marked variation in metabolome diversity at the seasonal level, with summer and autumn being the periods with higher metabolite diversity compared to winter and spring. We conclude that both the environmental variation throughout the year in combination with the structure of the ecological niche are relevant to understand the variation in expression of metabolites in plants.

Comparative study on erythrogram parameters of Cell-Dyn Ruby and Humacount 5l / Estudio comparativo de los parámetros del eritrograma de Cell-Dyn Ruby y Humacount 5l

SUMMARY: The use of hematological counts for the prevention, diagnosis and follow-up of hematological diseases has increased. Indeed, the correct operation of a clinical laboratory is essential to producing comparable results. However, there is a paucity of validation and reproducibility studies among the different existing methods for clinical analysis. Therefore, our aim was to assess the commutability of the results provided by analyzers with different measuring systems. Sixty venous blood samples were obtained from patients, without discriminating for age or sex. Then, an automated hematological analysis was performed using the Cell-Dyn Ruby and HumaCount 5L instruments. The variables measured were: RBC, Hb, HCT, MCV, MCH and MCHC. The data were compared by a one-way ANOVA and Pearson's correlation coefficient. Statistical significance was fixed at p < 0.05. There were no statistically significant differences for RBC, HCT, MCH or MCHC. In addition, with the exception of MCHC, all the analytes showed a good correlation coefficient between the two instruments. There is a variety of automated systems for the clinical laboratory and it is essential for the clinician to know the different methodologies used in hematological analyzers as well as their sensitivity and specificity. Therefore, our results are useful for demonstrating the importance of practical knowledge of the analyzers mentioned.

RESUMEN: El uso de recuentos de células sanguíneas para la prevención, diagnóstico y monitoreo de enfermedades hematológicas ha ido en aumento. Por ello, el funcionamiento correcto de un laboratorio clínico es indispensable para producir resultados comparables. Sin embargo, existen pocos estudios de validación y reproducibilidad de los diferentes métodos de análisis clínico existentes. Por lo tanto, nuestro objetivo fue evaluar la intercambiabilidad de los resultados entregados por los analizadores que utilizan diferentes sistemas de medición. Se obtuvieron sesenta muestras de sangre venosa de pacientes, sin discriminar por edad o sexo. Los eritrogramas fueron obtenidos utilizando los analizadores automatizados Cell-Dyn Ruby y HumaCount 5L. Las variables medidas fueron: RBC, Hb, HCT, MCV, MCH y MCHC. Los datos fueron comparados por ANOVA a una vía y la correlación de Pearson. La significación estadística se estableció en el nivel estándar p<0,05. No hubo diferencias estadísticamente sig- nificativas para RBC, HCT, MCH y MCHC. Con la excepción de la MCHC, todos los analitos presentaron un buen coeficiente de correlación entre los dos analizadores comparados. Existen varios sistemas de automatización para su uso en laboratorios clínicos. Por lo tanto, es primordial para el clínico estar familiarizado con las diferentes metodologías utilizadas en los analizadores de sangre, así como su sensibilidad y especificidad. Nuestros resultados son útiles para mostrar la importancia del conocimiento práctico de los diferentes sistemas de medidas comparados.

The identity of the Chilean Amphibians collected by the United States exploring expedition.

Between mid-May and early June of 1839, members of the United States Exploring Expedition collected diverse anurans in the environs of Valparaíso, Chile, later described by Girard in 1853. Of this set of species, Metaeus timidus, described there as a new genus and species, attracts attention because is a name that practically disappeared from the herpetological literature. Its identification, along with that of the other Chilean taxa collected by the USEE (Cystignathus nebulosus Girard, 1853, Pleurodema bibroni Tschudi, 1838, Pleurodema elegans Bell, 1843, Bufo lugubrosus Girard, 1853, Bufo thaul Lesson, 1826 and Metaeus timidus Girard, 1853) are the main objectives of this contribution.

Caracterización clínica de la meningitis aguda de la comunidad causada por Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae y Listeria monocytogenes en adultos en el Hospital Carlos van Buren entre los años 2013 y 2016 / Clinical characteristics of community-acquired acute meningitis caused by Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae and Listeria monocytogenes in adults in Carlos van Buren Hospital between 2013-2016

INTRODUCCIÓN: la meningitis bacteriana es una enfermedad infecciosa aguda grave, que por su letalidad y costos en atención de salud genera un alto impacto en Salud Pública. Los agentes causales más frecuentes son Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae y Listeria monocytogenes, pero poco conocemos de nuestra realidad local. MATERIALES Y MÉTODOS: estudio descriptivo, con revisión de base de datos del laboratorio de microbiología del Hospital Carlos Van Buren, obteniendo datos de los cultivos de líquido céfalo raquídeo de pacientes mayores de 15 años entre marzo de 2013 y noviembre de 2016. RESULTADOS: 128 casos de meningitis bacteriana aguda, de los cuales 17 fueron por los microorganismos objetivos del estudio, siendo el más frecuente S. pneumoniae, clínicamente un 58% se presentó sin signos meníngeos. A 30 días del diagnóstico un 35% había fallecido, la mitad de ellos inició el tratamiento antibiótico pasadas las 24 horas desde su ingreso al hospital. En el 46% la tinción gram no evidenció bacterias. DISCUSIÓN: los microorganismos clásicamente descritos como agentes causales parecen no explicar la totalidad de los cuadros de meningitis bacteriana aguda en la población adulta estudiada, la ausencia de signos meníngeos no permite descartar la sospecha diagnóstica. La mitad de los pacientes fallecidos inició el tratamiento antibiótico pasadas las primeras 24 horas.

INTRODUCTION: bacterial meningitis is a serious acute infectious disease whose lethality and elevated health costs have a serious impact on public health. The most frequent causes are Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenza and Listeria monocytogenes, but we know little of the local situation. MATERIALS AND METHODS: A descriptive study reviewing Carlos van Buren Hospital´s microbiology laboratory data base, and obtaining the details of cerebrospinal fluid cultures of patients over the age of 15 between March 2013 and November 2016. RESULTS: 128 cases of acute bacterial meningitis of which 17% were caused by the micro-organisms of study, the most frequent being Streptococcus pneumoniae. 58% of patients had no meningeal signs. At 30 days from diagnosis 35% had died, half of these having started antibiotic treatment over 24 hours after admission. 46% of the Gram stains showed no bacteria. DISCUSSION: the classical infectious agents do not appear to account for the totality of acute bacterial meningitis in the population studied. The absence of meningeal signs should not rule out the diagnosis. Half of the patients who died started antibiotic treatment after the first 24 hours.

Species delimitation in frogs from South American temperate forests: The case of Eupsophus, a taxonomically complex genus with high phenotypic variation.

One of the most characteristic and abundant amphibian taxa of South American temperate forests is Eupsophus. The ten currently recognized species of the genus have been divided in two species groups, roseus and vertebralis, but most of them, eight, belong to the roseus group. Recent phylogeographic and phylogenetic studies have suggested that species diversity of the roseus group could be underestimated. An examination of the literature shows that species of the roseus group exhibit high levels of variation in their external characteristics, particularly those used as diagnostic characters, which compromises their taxonomy and hinders their field recognition. High levels of variation were also observed in several new populations of the roseus group discovered in southern Chile (36°-40°S), which could not be identified to the species level by their external characteristics. On the other hand, the literature reveals a scarse karyotype differentiation and a high bioacoustic uniformity among the species of the roseus group. We performed a Bayesian phylogenetic analysis using mitochondrial and nuclear genes to reevaluate the species diversity of the roseus group, including all the nominal species of Eupsophus and new populations. This analysis was complemented with three species delimitation approaches, General Mixed Yule Coalescent, multi-rate Poisson Tree Process and Automatic Barcode Gap Discovery. We favored a conservative delimitation of only four species for the roseus group, a result more consistent with the distribution of pairwise genetic distances, and the available chromosome and bioacoustic evidence. The four recognized lineages, which have nearly completely allopatric distributions, are named after the earliest nominal species that they include, but because high levels of phenotypic variation, they are not diagnosable by consistent differences in external morphology. We discuss the implications of this new proposal for the taxonomy and conservation of the genus, and the possible causes of the difficulty to estimate its species diversity.