Endothelial activation impairs the function of small extracellular vesicles

Small extracellular vesicles are nanosized vesicles (30–200 nm) that can ferry proteins, nucleic acids, and lipids between cells and therefore, have significant potential as biomarkers, drug delivery tools or therapeutic agents. SEVs of endothelial origin have been shown to -among other functions-reduce in vitro ischemia/reperfusion (I/R) injury in cardiomyocytes, but whether a pro-inflammatory state of the endothelium impairs the functionality of these SEVs remains to be elucidated. To test this, human umbilical vein endothelial cells cells were treated with TNF-α 10 ng/mL and the expression of the pro-inflammatory parameters VCAM-1, ICAM-1 and eNOS were determined by Western blot. SEVs were isolated from endothelial cells treated with or without TNF-α 10 ng/mL using size exclusion chromatography. The size and concentration of SEVs was measured by Nanoparticle Tracking Analysis. The expression of the surface marker CD81 was determined by immunoassay, whereas their morphology was assessed by electron microscopy. The function of endothelial SEVs was assessed by evaluating their cardioprotective effect in an ex vivo model of global I/R using isolated hearts from adult C57BL/6 mice. Treatment of HUVECs with TNF-α induced the expression of VCAM-1 and ICAM-1, whereas eNOS levels were decreased. TNF-α did not affect the production, size, morphology, or expression of CD81. SEVs significantly reduced the infarct size as compared with untreated mice hearts, but SEVs isolated from TNF-α treated cells were unable to achieve this effect. Therefore, a pro-inflammatory state induced by TNF-α does not alter the production of endothelial SEVs but impairs their function in the setting of I/R injury

La propuesta reducción del límite máximo permitido de células somáticas en leche cruda y su posible efecto sobre la industria lechera en Puerto Rico.

Data from 302,995 test day records of individual cows of the Puerto Rico Dairy Herd Improvement Program (PRDHIP) and from 8,833 bulk tank results from all herds in Puerto Rico during the years 2004 and 2005 were analyzed for determining the potential effect of implementation of the National Mastitis Council's (NMC) proposal to reduce the present regulatory upper limit for somatic cell count of 750,000 cells/ml of crude milk. Means of herd test day milk yield per cow and of somatic cell scores on the linear scale for this data set were 17.2 kg and 3.9, respectively. On the basis of PRDHIP data, it was estimated that 20% of individual test day values, equivalent to 920,290 kg of raw milk, would exceed the upper limit if it were established at 600,000 cells/ml. The months of highest average milk production were February, March and May (18.4,18.2 and 18.2 kg/day, respectively).The lowest production was observed in August, September and October (16.3,15.6 and 15.8 kg/day, respectively). The months with the lowest average somatic cell score were February and April (both at 3.5) and those of the highest were August, September and October (4.2,4.2 and 4.3, respectively). The average somatic cell counts for herds enrolled or not enrolled in DHIP were similar (461,656 and 473,096, respectively; P greater than 0.05).Se analizaron datos de 302,995 pesajes individuales de leche de vacas de hatos acogidos al Programa de Mejoramiento de Hatos Lecheros de Puerto Rico (PRDHIP, por sus siglas en inglés) y 8,833 resultados de análisis de recuentos de células somáticas (RCS) de muestras de tanque de todas las operaciones lecheras de Puerto Rico durante los años 2004 y 2005 para determinar el efecto potencial que tendría la aplicación de la propuesta del Concilio Nacional de Mastitis (NMC) de reducir el límite máximo actual de 750,000 células por mililitro de leche cruda. Los promedios de producción diaria de leche por vaca y de los recuentos de células somáticas expresados en la escala lineal (RLCS) en este conjunto de datos fueron 17.2 kg y 3.9, respectivamente. Basado en los registros del DHIP, se estimó en un 20% la proporción de pesajes de vacas individuales, equivalentes a 920,290 kg de leche cruda, que estaría fuera de norma si el límite máximo permitido se redujera a 600,000 células somáticas por mililitro. Los meses de mayor producción promedio de leche fueron febrero, marzo y mayo (18.4, 18.2 y 18.2 kg/día, respectivamente), mientras que las producciones menores se registraron en los meses de agosto, septiembre y octubre (16.3,15.6 y 15.8 kg/día, respectivamente). Los meses con los menores promedios de RLCS correspondieron a febrero y abril (ambos en 3.5) y los mayores a agosto, septiembre y octubre (4.2, 4.2 y 4.3, respectivamente). El promedio de los RCS de muestras de tanque de los hatos acogidos o no al DHIA difirieron poco (461,656 y 473,096, respectivamente; P mayor que 0.05)

Nivel de sesgos cognitivos de representatividad y confirmación en estudiantes de Psicología de tres universidades del Bío-Bío

Cognitive biases are unreasonable ways of making decisions, often in a one-sided way. The objective of this research was to describe the level of representativeness and confirmation biases in Chilean psychology students, in order to know how this phenomenon occurs. The participants were 198 psychology students from three universities in southern Chile. The instrument was based on two cognitive tasks derived from Kanheman and Tversky. The data were analyzed through descriptive statistics and mean differences. The results indicate a high level of biases in the groups of students, in the two tasks evaluated; the representativeness bias presents differences among universities only in sub-task 1, as well as in task 2, related to confirmation bias. Likewise, there are differences in representation bias according to age and sex. The need to strengthen reasoning skills in the initial training of future psychologists, in order to improve skills related to decision making in the professional field is concluded.Los sesgos cognitivos son formas no razonadas de tomar decisiones, a menudo de manera parcializada. El objetivo de esta investigación fue describir el nivel de sesgos de representatividad y confirmación en estudiantes de psicología chilenos, para conocer cómo se presenta este fenómeno. Los participantes fueron 198 estudiantes de psicología, de tres universidades del sur de Chile. El instrumento se basó en dos tareas cognitivas derivadas de Kanheman y Tversky; se analizaron los datos con estadística descriptiva y diferencias de medias. Los resultados indican alto nivel de sesgos en los grupos de estudiantes, en las dos tareas evaluadas; el sesgo de representatividad presenta diferencias entre universidades, solo en la subtarea 1, así como en la tarea 2, relacionada con sesgo de confirmación; así mismo se observan diferencias en sesgo de representación según edad y sexo. Se concluye la necesidad de fortalecer habilidades de razonamiento en la formación inicial de los futuros psicólogos y psicólogas, con la finalidad de mejorar las habilidades relacionadas con la toma de decisiones en el campo profesional

Nivel de sesgos cognitivos de representatividad y confirmación en estudiantes de Psicología de tres universidades del Bío-Bío

Cognitive biases are unreasonable ways of making decisions, often in a one-sided way. The objective of this research was to describe the level of representativeness and confirmation biases in Chilean psychology students, in order to know how this phenomenon occurs. The participants were 198 psychology students from three universities in southern Chile. The instrument was based on two cognitive tasks derived from Kanheman and Tversky. The data were analyzed through descriptive statistics and mean differences. The results indicate a high level of biases in the groups of students, in the two tasks evaluated; the representativeness bias presents differences among universities only in sub-task 1, as well as in task 2, related to confirmation bias. Likewise, there are differences in representation bias according to age and sex. The need to strengthen reasoning skills in the initial training of future psychologists, in order to improve skills related to decision making in the professional field is concluded.Los sesgos cognitivos son formas no razonadas de tomar decisiones, a menudo de manera parcializada. El objetivo de esta investigación fue describir el nivel de sesgos de representatividad y confirmación en estudiantes de psicología chilenos, para conocer cómo se presenta este fenómeno. Los participantes fueron 198 estudiantes de psicología, de tres universidades del sur de Chile. El instrumento se basó en dos tareas cognitivas derivadas de Kanheman y Tversky; se analizaron los datos con estadística descriptiva y diferencias de medias. Los resultados indican alto nivel de sesgos en los grupos de estudiantes, en las dos tareas evaluadas; el sesgo de representatividad presenta diferencias entre universidades, solo en la subtarea 1, así como en la tarea 2, relacionada con sesgo de confirmación; así mismo se observan diferencias en sesgo de representación según edad y sexo. Se concluye la necesidad de fortalecer habilidades de razonamiento en la formación inicial de los futuros psicólogos y psicólogas, con la finalidad de mejorar las habilidades relacionadas con la toma de decisiones en el campo profesional

High-Fat-Diet-Induced Obesity Produces Spontaneous Ventricular Arrhythmias and Increases the Activity of Ryanodine Receptors in Mice

Ventricular arrhythmias are a common cause of sudden cardiac death, and their occurrence is higher in obese subjects. Abnormal gating of ryanodine receptors (RyR2), the calcium release channels of the sarcoplasmic reticulum, can produce ventricular arrhythmias. Since obesity promotes oxidative stress and RyR2 are redox-sensitive channels, we investigated whether the RyR2 activity was altered in obese mice. Mice fed a high fat diet (HFD) became obese after eight weeks and exhibited a significant increase in the occurrence of ventricular arrhythmias. Single RyR2 channels isolated from the hearts of obese mice were more active in planar bilayers than those isolated from the hearts of the control mice. At the molecular level, RyR2 channels from HFD-fed mice had substantially fewer free thiol residues, suggesting that redox modifications were responsible for the higher activity. Apocynin, provided in the drinking water, completely prevented the appearance of ventricular arrhythmias in HFD-fed mice, and normalized the activity and content of the free thiol residues of the protein. HFD increased the expression of NOX4, an isoform of NADPH oxidase, in the heart. Our results suggest that HFD increases the activity of RyR2 channels via a redox-dependent mechanism, favoring the appearance of ventricular arrhythmias.Fil: Pecchi Sanchez, Gina Angela. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomédicas; ChileFil: Araneda, Felipe. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomédicas; ChileFil: Peña, Juan Pedro. Universidad de Viña del Mar. Escuela de Ciencias Veterinarias; ChileFil: Finkelstein, Jose Pablo. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomédicas; ChileFil: Riquelme, Jaime A.. Universidad de Chile; ChileFil: Montecinos, Luis. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomédicas; ChileFil: Barrientos, Genaro. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomédicas; ChileFil: LLanos, Paola. Universidad de Chile; ChileFil: Pedrozo, Zully. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomédicas; ChileFil: Said, Maria Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Bull, Ricardo. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomédicas; ChileFil: Donoso, Paulina. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomédicas; Chil

Factors structuring microbial communities in highly impacted coastal marine sediments (Mar Menor lagoon, SE Spain)

Coastal marine lagoons are environments highly vulnerable to anthropogenic pressures such as agriculture nutrient loading or runoff from metalliferous mining. Sediment microorganisms, which are key components in the biogeochemical cycles, can help attenuate these impacts by accumulating nutrients and pollutants. The Mar Menor, located in the southeast of Spain, is an example of a coastal lagoon strongly altered by anthropic pressures, but the microbial community inhabiting its sediments remains unknown. Here, we describe the sediment prokaryotic communities along a wide range of environmental conditions in the lagoon, revealing that microbial communities were highly heterogeneous among stations, although a core microbiome was detected. The microbiota was dominated by Delta- and Gammaproteobacteria and members of the Bacteroidia class. Additionally, several uncultured groups such as Asgardarchaeota were detected in relatively high proportions. Sediment texture, the presence of Caulerpa or Cymodocea, depth, and geographic location were among the most important factors structuring microbial assemblages. Furthermore, microbial communities in the stations with the highest concentrations of potentially toxic elements (Fe, Pb, As, Zn, and Cd) were less stable than those in the non-contaminated stations. This finding suggests that bacteria colonizing heavily contaminated stations are specialists sensitive to change

Exploring plant responses to abiotic stress by contrasting spectral signature changes

In this study, daily changes over a short period and diurnal progression of spectral reflectance at the leaf level were used to identify spring wheat genotypes (Triticum aestivum L.) susceptible to adverse conditions. Four genotypes were grown in pots experiments under semi-controlled conditions in Chile and Spain. Three treatments were applied: i) control (C), ii) water stress (WS), and iii) combined water and heat shock (WS+T). Spectral reflectance, gas exchange and chlorophyll fluorescence measurements were performed on flag leaves for three consecutive days at anthesis. High canopy temperature (HCT) genotypes showed less variability in their mean spectral reflectance signature and chlorophyll fluorescence, which was related to weaker responses to environmental fluctuations. While low canopy temperature (LCT) genotypes showed greater variability. The genotypes spectral signature changes, in accordance with environmental fluctuation, were associated with variations in their stomatal conductance under both stress conditions (WS and WS+T); LCT genotypes showed an anisohydric response compared that of HCT, which was isohydric. This approach could be used in breeding programs for screening a large number of genotypes through proximal or remote sensing tools and be a novel but simple way to identify groups of genotypes with contrasting performances

Different Chitin Synthase Genes Are Required for Various Developmental and Plant Infection Processes in the Rice Blast Fungus Magnaporthe oryzae

Chitin is a major component of fungal cell wall and is synthesized by chitin synthases (Chs). Plant pathogenic fungi normally have multiple chitin synthase genes. To determine their roles in development and pathogenesis, we functionally characterized all seven CHS genes in Magnaporthe oryzae. Three of them, CHS1, CHS6, and CHS7, were found to be important for plant infection. While the chs6 mutant was non-pathogenic, the chs1 and chs7 mutants were significantly reduced in virulence. CHS1 plays a specific role in conidiogenesis, an essential step for natural infection cycle. Most of chs1 conidia had no septum and spore tip mucilage. The chs6 mutant was reduced in hyphal growth and conidiation. It failed to penetrate and grow invasively in plant cells. The two MMD-containing chitin synthase genes, CHS5 and CHS6, have a similar expression pattern. Although deletion of CHS5 had no detectable phenotype, the chs5 chs6 double mutant had more severe defects than the chs6 mutant, indicating that they may have overlapping functions in maintaining polarized growth in vegetative and invasive hyphae. Unlike the other CHS genes, CHS7 has a unique function in appressorium formation. Although it was blocked in appressorium formation by germ tubes on artificial hydrophobic surfaces, the chs7 mutant still produced melanized appressoria by hyphal tips or on plant surfaces, indicating that chitin synthase genes have distinct impacts on appressorium formation by hyphal tip and germ tube. The chs7 mutant also was defective in appressorium penetration and invasive growth. Overall, our results indicate that individual CHS genes play diverse roles in hyphal growth, conidiogenesis, appressorium development, and pathogenesis in M. oryzae, and provided potential new leads in the control of this devastating pathogen by targeting specific chitin synthases

Trubadurlyrikens skrattspegel. Några exempel på det obscena elementet i medeltida occitansk trubadurlyrik

Abstract Extracellular vesicles (EVs) such as exosomes are nano-sized vesicles that carry proteins and miRNAs and can transmit signals between cells. We hypothesized that exosomes from endothelial cells can transmit protective signals to cardiomyocytes. Co-culture of primary adult rat cardiomyocytes with normoxic HUVEC cells separated by a cell-impermeable membrane reduced the percentage of cardiomyocyte death following simulated ischaemia and reperfusion (sIR) from 80 ± 11% to 51 ± 4% (P < 0.05; N = 5). When EVs were removed from the HUVEC-conditioned medium it was no longer protective. Exosomes were purified from HUVEC-conditioned medium using differential centrifugation and characterized by nanoparticle tracking analysis, electron microscopy, and flow cytometry. Pre-incubation of cardiomyocytes with HUVEC exosomes reduced the percentage of cell death after sIR from 88 ± 4% to 55 ± 3% (P < 0.05; N = 3). This protection required ERK1/2 activity as it was prevented by inhibitors PD98059 and U0126. Ischaemic preconditioning caused about ~3-fold higher rate of exosome production from HUVEC and from isolated, perfused rat hearts. This increase resulted in significantly greater protection against sIR in cardiomyocytes. In conclusion, exosomes released from endothelial cells can confer resistance to sIR injury in cardiomyocytes via the activation of the ERK1/2 MAPK signalling pathway, and may contribute to IPC