Contrasting evolutionary responses in two co-distributed species of Galaxias (Pisces, Galaxiidae) in a river from the glaciated range in Southern Chile.

Life-history traits are among the most important factors affecting population abundance and genetic diversity of species. Here, we analysed the genetic patterns of two Galaxias species with different life-history traits to investigate how these biological differences impacted their evolution in the Valdivia River basin, Southern Chile. We analysed mitochondrial DNA (mtDNA) sequences from 225 individuals of Galaxias maculatus and 136 of G. platei to compare patterns of genetic diversity, structure and demographic growth across the basin. Galaxias maculatus presented higher genetic diversity and higher genetic structure than G. platei. Demographic analyses showed G. maculatus kept a higher population size over time, with a signal of demographic expansion in the last 250 kyr. Whereas Galaxias platei, exhibited lower, but constant population size over time. Furthermore, haplotype networks revealed higher lineage diversity in G. maculatus with a tendency to occupy different areas of the basin. Coalescent simulations ruled out that genetic differences between species could be explained by stochastic processes (genetic drift), suggesting species-specific biological differences as responsible for the observed genetic differences. We discuss how differences in life-history traits and past glaciations interact to shape the evolutionary history of the two Galaxias species.

Relación entre sobrecarga hídrica y mortalidad en niños conshock séptico / Relation between fluid overload and mortality in children with septic shock

El shock séptico es una de las principales causas que puede llevar a la muerte. La reanimación hídrica constituye un destacado tratamiento para poder disminuir la mortalidad. Objetivo: determinar la relación entre el porcentaje de sobrecarga hídrica (%SH) y la mortalidad en niños con shock séptico. Métodos. Estudio de cohorte en pacientes con shock séptico de entre 1 y 17 años, posterior a la reanimación hídrica con presión venosa central ≥ 5 mmHg con monitoreo invasivo y registro completo de %SH hasta las 96 h. El seguimiento y la variable de desenlace se completaron hasta el día 28. Se registraron las siguientes variables del shock séptico, shock refractario, causa de la insuficiencia renal aguda, anemia, desnutrición, el tiempo de inicio de antimicrobiano, presión oncótica y puntaje de gravedad. Análisis estadístico: Se calculó el hazard ratio (HR) y se construyeron tres modelos pronósticos por riesgos proporcionales de Cox. Resultados. La población fue de 263 pacientes; con un promedio de edad de 8 ± 3 años y con mortalidad del 33 %. El %SH ≥ 10,1 acumulado a las 96 h fue el único asociado; el HR (IC 95 %) ajustado fue perfil hemodinámico HR = 2,6 (1,95,6); por shock refractario, HR = 2,5 (1,6-5,6) y por desnutrición, HR = 8,3 (3,5-14). Conclusiones. El %SH > 10,1 % se relacionó con una mayor mortalidad a 28 días de ajustado al perfil hemodinámico, la refractariedad del shock y el estado nutricional.

Septic shock is one of the main causes of mortality. Fluid replacement stands out as the treatment of choice to reduce mortality. Objective. To determine the relation between the percentage of fluid overload (%FO) and mortality in children with septic shock. Methods. Cohort study in patients aged 1-17 years with septic shock, after fluid replacement with central venous pressure ≥ 5 mmHg, invasive monitoring, and complete recording of %FO up to 96 h. Follow-up and outcome measures were recorded up to day 28. The following outcome measures of septic shock were recorded: refractory shock, cause of acute kidney injury, anemia, malnutrition, time to antibiotic initiation, oncotic pressure, and severity score. Statistical analysis. The hazard ratio (HR) was estimated and three Cox proportional hazard models were developed. Results. The population included 263 patients; their average age was 8 ± 3 years. Mortality was 33 %. A %FO ≥ 10.1 % accumulated at 96 h was the only associated outcome measure; the HR (95 % confidence interval) was adjusted for hemodynamic profile, HR = 2.6 (1.95.6); refractory shock, HR = 2.5 (1.6-5.6); and malnutrition, HR = 8.3 (3.5-14). Conclusions. A %FO > 10.1 % was related to a higher mortality at 28 days of adjustment for hemodynamic profile, refractory shock, and nutritional status.

Relation between fluid overload and mortality in children with septic shock. / Relación entre sobrecarga hídrica y mortalidad en niños conshock séptico.

INTRODUCTION: Septic shock is one of the main causes of mortality. Fluid replacement stands out as the treatment of choice to reduce mortality. OBJECTIVE: To determine the relation between the percentage of fluid overload (%FO) and mortality in children with septic shock. METHODS: Cohort study in patients aged 1-17 years with septic shock, after fluid replacement with central venous pressure ≥ 5 mmHg, invasive monitoring, and complete recording of %FO up to 96 h. Follow-up and outcome measures were recorded up to day 28. The following outcome measures of septic shock were recorded: refractory shock, cause of acute kidney injury, anemia, malnutrition, time to antibiotic initiation, oncotic pressure, and severity score. STATISTICAL ANALYSIS AND METHODS: The hazard ratio (HR) was estimated and three Cox proportional hazard models were developed. RESULTS: The population included 263 patients; their average age was 8 ± 3 years. Mortality was 33 %. A %FO ≥ 10.1 % accumulated at 96 h was the only associated outcome measure; the HR (95 % confidence interval) was adjusted for hemodynamic profile, HR = 2.6 (1.95.6); refractory shock, HR = 2.5 (1.6-5.6); and malnutrition, HR = 8.3 (3.5-14). CONCLUSIONS: A %FO > 10.1 % was related to a higher mortality at 28 days of adjustment for hemodynamic profile, refractory shock, and nutritional status.

El shock séptico es una de las principales causas que puede llevar a la muerte. La reanimación hídrica constituye un destacado tratamiento para poder disminuir la mortalidad. Objetivo: determinar la relación entre el porcentaje de sobrecarga hídrica (%SH) y la mortalidad en niños con shock séptico. Métodos. Estudio de cohorte en pacientes con shock séptico de entre 1 y 17 años, posterior a la reanimación hídrica con presión venosa central ≥ 5 mmHg con monitoreo invasivo y registro completo de %SH hasta las 96 h. El seguimiento y la variable de desenlace se completaron hasta el día 28. Se registraron las siguientes variables del shock séptico, shock refractario, causa de la insuficiencia renal aguda, anemia, desnutrición, el tiempo de inicio de antimicrobiano, presión oncótica y puntaje de gravedad. Análisis estadístico: Se calculó el hazard ratio (HR) y se construyeron tres modelos pronósticos por riesgos proporcionales de Cox. Resultados. La población fue de 263 pacientes; con un promedio de edad de 8 ± 3 años y con mortalidad del 33 %. El %SH ≥ 10,1 acumulado a las 96 h fue el único asociado; el HR (IC 95 %) ajustado fue perfil hemodinámico HR = 2,6 (1,95,6); por shock refractario, HR = 2,5 (1,6-5,6) y por desnutrición, HR = 8,3 (3,5-14). Conclusiones. El %SH > 10,1 % se relacionó con una mayor mortalidad a 28 días de ajustado al perfil hemodinámico, la refractariedad del shock y el estado nutricional.

Desarrollo y validación de la Escala de Mortalidad Neonatal-9 México para predecir la mortalidad en neonatos críticamente enfermos / Development and validation of the Neonatal Mortality Score-9 Mexico to predict mortality in critically ill neonates

Introducción. Las escalas pronósticas son de utilidad para el médico que ejerce en las unidades de cuidados intensivos neonatales. Existen escalas neonatales validadas, en su mayoría para neonatos de bajo peso al nacer. El objetivo fue crear y validar una escala predictora de mortalidad en neonatos que incluyera nuevas variables pronósticas. Población y métodos. Se realizó el estudio en un hospital materno-infantil de la ciudad de México, del Instituto Mexicano del Seguro Social. En la primera fase, se diseñó un estudio de casos y controles anidado en una cohorte (neonatos ingresados con criterios de gravedad durante el primer día de vida), en el que se identificó y construyó una escala con parámetros graduales de puntuación acumulativa de nueve variables independientes para predecir muerte: peso, acidemia metabólica, lactato, paO2/FiO2, p(A-a) O2, A/a, plaquetas y glucosa sérica. La validación se realizó en una cohorte prospectiva, de las mismas características, tomando como variable de desenlace la mortalidad hasta el séptimo día. Resultados. La cohorte incipiente estuvo conformada por 424 neonatos. Se seleccionaron 22 casos y 132 controles, y se identificaron 9 variables, que conformaron la escala nombrada escala de mortalidad neonatal-9 México. La cohorte de validación estuvo integrada por 227 neonatos. Se registraron 44 (19%) defunciones, con un área bajo la curva de 0,92. Con una puntuación de entre 16 y 18, se reportó un hazard ratio de 85 (11-102), una especificidad de 99%, un valor predictivo positivo de 71% y un valor predictivo negativo de 90%. Conclusiones. La escala propuesta es un instrumento fiable para predecir la gravedad en neonatos.

Introduction. Prognostic scales or scores are useful for physicians who work in neonatal intensive care units. There are several validated neonatal scores but they are mostly applicable to low birth weight infants. The aim of this study was to develop and validate a mortality prognostic score in newborn infants, that would include new prognostic outcome measures. Population and Methods. The study was conducted in a mother and child hospital in the city of Mexico, part of the Instituto Mexicano del Seguro Social (Mexican Institute of Social Security). In the first phase of the study, a nested case-control study was designed (newborn infants admitted on the basis of severity criteria during the first day of life), in which a scale was identified and developed with gradual parameters of cumulative score consisting of nine independent outcome measures to predict death, as follows: weight, metabolic acidemia, lactate, PaO2/FiO2, p(A-a) O2, A/a, platelets and serum glucose.Validation was performed in a matched prospective cohort, using 7-day mortality as an endpoint. Results. The initial cohort consisted of 424 newborn infants. Twenty-two cases and 132 controls were selected; and 9 outcome measures were identified, making up the scale named neonatal mortality score-9 Mexico. The validation cohort consisted of 227 newborn infants. Forty-four (19%) deaths were recorded, with an area under the curve (AUC) of 0.92. With a score between 16 and 18, an 85 (11-102) hazard ratio, 99% specificity, 71% positive predictive value and 90% negative predictive value were reported. Conclusions .The proposed scale is a reliable tool to predict severity in newborn infants.

Desarrollo y validación de la Escala de Mortalidad Neonatal-9 México para predecir la mortalidad en neonatos críticamente enfermos / Development and validation of the Neonatal Mortality Score-9 Mexico to predict mortality in critically ill neonates

Introducción. Las escalas pronósticas son de utilidad para el médico que ejerce en las unidades de cuidados intensivos neonatales. Existen escalas neonatales validadas, en su mayoría para neonatos de bajo peso al nacer. El objetivo fue crear y validar una escala predictora de mortalidad en neonatos que incluyera nuevas variables pronósticas. Población y métodos. Se realizó el estudio en un hospital materno-infantil de la ciudad de México, del Instituto Mexicano del Seguro Social. En la primera fase, se diseñó un estudio de casos y controles anidado en una cohorte (neonatos ingresados con criterios de gravedad durante el primer día de vida), en el que se identificó y construyó una escala con parámetros graduales de puntuación acumulativa de nueve variables independientes para predecir muerte: peso, acidemia metabólica, lactato, paO2/FiO2, p(A-a) O2, A/a, plaquetas y glucosa sérica. La validación se realizó en una cohorte prospectiva, de las mismas características, tomando como variable de desenlace la mortalidad hasta el séptimo día. Resultados. La cohorte incipiente estuvo conformada por 424 neonatos. Se seleccionaron 22 casos y 132 controles, y se identificaron 9 variables, que conformaron la escala nombrada escala de mortalidad neonatal-9 México. La cohorte de validación estuvo integrada por 227 neonatos. Se registraron 44 (19%) defunciones, con un área bajo la curva de 0,92. Con una puntuación de entre 16 y 18, se reportó un hazard ratio de 85 (11-102), una especificidad de 99%, un valor predictivo positivo de 71% y un valor predictivo negativo de 90%. Conclusiones. La escala propuesta es un instrumento fiable para predecir la gravedad en neonatos.(AU)

Introduction. Prognostic scales or scores are useful for physicians who work in neonatal intensive care units. There are several validated neonatal scores but they are mostly applicable to low birth weight infants. The aim of this study was to develop and validate a mortality prognostic score in newborn infants, that would include new prognostic outcome measures. Population and Methods. The study was conducted in a mother and child hospital in the city of Mexico, part of the Instituto Mexicano del Seguro Social (Mexican Institute of Social Security). In the first phase of the study, a nested case-control study was designed (newborn infants admitted on the basis of severity criteria during the first day of life), in which a scale was identified and developed with gradual parameters of cumulative score consisting of nine independent outcome measures to predict death, as follows: weight, metabolic acidemia, lactate, PaO2/FiO2, p(A-a) O2, A/a, platelets and serum glucose.Validation was performed in a matched prospective cohort, using 7-day mortality as an endpoint. Results. The initial cohort consisted of 424 newborn infants. Twenty-two cases and 132 controls were selected; and 9 outcome measures were identified, making up the scale named neonatal mortality score-9 Mexico. The validation cohort consisted of 227 newborn infants. Forty-four (19%) deaths were recorded, with an area under the curve (AUC) of 0.92. With a score between 16 and 18, an 85 (11-102) hazard ratio, 99% specificity, 71% positive predictive value and 90% negative predictive value were reported. Conclusions .The proposed scale is a reliable tool to predict severity in newborn infants.(AU)

Development and validation of the Neonatal Mortality Score-9 Mexico to predict mortality in critically ill neonates.

INTRODUCTION: Prognostic scales or scores are useful for physicians who work in neonatal intensive care units. There are several validated neonatal scores but they are mostly applicable to low birth weight infants. The aim of this study was to develop and validate a mortality prognostic score in newborn infants, that would include new prognostic outcome measures. POPULATION AND METHODS: The study was conducted in a mother and child hospital in the city of Mexico, part of the Instituto Mexicano del Seguro Social (Mexican Institute of Social Security). In the first phase of the study, a nested case-control study was designed (newborn infants admitted on the basis of severity criteria during the first day of life), in which a scale was identified and developed with gradual parameters of cumulative score consisting of nine independent outcome measures to predict death, as follows: weight, metabolic acidemia, lactate, PaO2/FiO2, p(A-a) O2, A/a, platelets and serum glucose.Validation was performed in a matched prospective cohort, using 7-day mortality as an endpoint. RESULTS: The initial cohort consisted of 424 newborn infants. Twenty-two cases and 132 controls were selected; and 9 outcome measures were identified, making up the scale named neonatal mortality score-9 Mexico. The validation cohort consisted of 227 newborn infants. Forty-four (19%) deaths were recorded, with an area under the curve (AUC) of 0.92. With a score between 16 and 18, an 85 (11-102) hazard ratio, 99% specificity, 71% positive predictive value and 90% negative predictive value were reported. Conclusions .The proposed scale is a reliable tool to predict severity in newborn infants.

New Records Reveal the Actual Distribution of Cratomelus meritus Gorochov (Orthoptera: Anostostomatidae), a Giant Red Cricket from Chile.

The geographic distribution of the red cricket Cratomelus meritus Gorochov had remained unknown until now due to mislabeling and lack of new records. The aim of this short communication is to uncover and establish the actual distribution of the species on the basis of new records and discuss potential biogeographic hypotheses about its distribution.

Phylogeography of the ancient catfish family Diplomystidae: biogeographic, systematic, and conservation implications.

The catfish family Diplomystidae is one of the earliest branching lineages within the diverse order Siluriformes and shows a deep phylogenetic split from all other extant and extinct major catfish groups. Despite its relevance in the evolution of siluriforms, phylogenetic relationships within the Diplomystidae are poorly understood, and prior to this study, no phylogenetic hypotheses using molecular data had been published. By conducting a phylogeographic study across the entire distribution of the family, that encompasses river systems from Central-South Chile and Argentina, we provide the first molecular phylogenetic hypothesis among all known species of Diplomystidae, and in addition, investigate how their evolutionary history relates to major historical events that took place in southern South America. Our phylogenetic analyses show four main lineages and nine sub-lineages strongly structured geographically. All Pacific basin populations, with one exception (those found in the Baker basin) clustered within three of the four main lineages (clades I-III), while all populations from Atlantic basins and those from the Baker basin clustered in a single main clade (clade IV). There was a tendency for genetic diversity to decrease from north to south for Pacific basins consistent with an increasing north-south ice coverage during the last glacial maximum. However, we did not find a statistically significant correlation between genetic diversity and latitude. Analysis of molecular variance (AMOVA) showed that river basins and the barrier created by the Andes Mountains explained a high percentage of the genetic variation. Interestingly, most of the genetic variation among drainages was explained among Pacific basins. Molecular phylogenetic analyses agree only partially with current systematics. The geographical distribution of main lineages did not match species distribution and suggests a new taxonomic hypothesis with support for four species of Diplomystes, three species distributed allopatrically from the Rapel to the Valdivia basin, and only one species distributed in Baker and Atlantic basins. High genetic differentiation among river basins suggests that conservation efforts should focus on protecting populations in each basin in order to preserve the genetic diversity of one of the oldest groups of catfishes on the earth today.