Aproximación a algunas variables hematológicas de “yaguaretés” (Panthera onca) cautivos en el nordeste argentino

Samples of three healthy Panthera onca from a Northeast Argentina reserve were analyzed through spectrophotometry, electrophoresis, densitometry, and microscopy in order to obtain hematological and biochemical reference values. Means and standard deviation for hematocrit, hemoglobin, red and white blood cells, leukocyte differential count, total protein, albumin, globulins, glucose, total cholesterol, lipoproteins, calcium, inorganic phosphorus, urea, creatinine and some enzymatic activities, were obtained. Usefulness of studied parameters to evaluate sanitary and nutritional state on captive P. onca, is emphasized.Muestras de tres ejemplares clínicamente sanos de Panthera onca alojados en una reserva del nordeste argentino, fueron analizadas por espectrofotometría, electroforesis, densitometría y microscopía para establecer intervalos de referencia hematológicos y bioquímicos. Se obtienen valores para hematocrito, hemoglobina, glóbulos rojos y blancos, fórmula leucocitaria, proteínas totales, albúmina, globulinas, glucosa, colesterol total, lipoproteínas, calcio, fósforo inorgánico, urea, creatinina y algunas actividades enzimáticas. Se enfatiza la utilidad de los parámetros estudiados para evaluar el estado sanitario y nutricional de P. onca en cautiverio.Fil: Mussart, Norma Beatriz. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Cátedra de Fisiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Koza, Gabriela Alejandra. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Cátedra de Fisiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Solis, G.. Ministerio de Industria. Secretaria de Industria y Comercio. Centro de Estudios Para la Produccion; ArgentinaFil: Coppo. J. A.. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Cátedra de Fisiología; Argentin

Roles of Candida albicans Mig1 and Mig2 in glucose repression, pathogenicity traits, and SNF1 essentiality.

Metabolic adaptation is linked to the ability of the opportunistic pathogen Candida albicans to colonize and cause infection in diverse host tissues. One way that C. albicans controls its metabolism is through the glucose repression pathway, where expression of alternative carbon source utilization genes is repressed in the presence of its preferred carbon source, glucose. Here we carry out genetic and gene expression studies that identify transcription factors Mig1 and Mig2 as mediators of glucose repression in C. albicans. The well-studied Mig1/2 orthologs ScMig1/2 mediate glucose repression in the yeast Saccharomyces cerevisiae; our data argue that C. albicans Mig1/2 function similarly as repressors of alternative carbon source utilization genes. However, Mig1/2 functions have several distinctive features in C. albicans. First, Mig1 and Mig2 have more co-equal roles in gene regulation than their S. cerevisiae orthologs. Second, Mig1 is regulated at the level of protein accumulation, more akin to ScMig2 than ScMig1. Third, Mig1 and Mig2 are together required for a unique aspect of C. albicans biology, the expression of several pathogenicity traits. Such Mig1/2-dependent traits include the abilities to form hyphae and biofilm, tolerance of cell wall inhibitors, and ability to damage macrophage-like cells and human endothelial cells. Finally, Mig1 is required for a puzzling feature of C. albicans biology that is not shared with S. cerevisiae: the essentiality of the Snf1 protein kinase, a central eukaryotic carbon metabolism regulator. Our results integrate Mig1 and Mig2 into the C. albicans glucose repression pathway and illuminate connections among carbon control, pathogenicity, and Snf1 essentiality

Mechanisms of Candida albicans Trafficking to the Brain

During hematogenously disseminated disease, Candida albicans infects most organs, including the brain. We discovered that a C. albicans vps51Δ/Δ mutant had significantly increased tropism for the brain in the mouse model of disseminated disease. To investigate the mechanisms of this enhanced trafficking to the brain, we studied the interactions of wild-type C. albicans and the vps51Δ/Δ mutant with brain microvascular endothelial cells in vitro. These studies revealed that C. albicans invasion of brain endothelial cells is mediated by the fungal invasins, Als3 and Ssa1. Als3 binds to the gp96 heat shock protein, which is expressed on the surface of brain endothelial cells, but not human umbilical vein endothelial cells, whereas Ssa1 binds to a brain endothelial cell receptor other than gp96. The vps51Δ/Δ mutant has increased surface expression of Als3, which is a major cause of the increased capacity of this mutant to both invade brain endothelial cells in vitro and traffic to the brain in mice. Therefore, during disseminated disease, C. albicans traffics to and infects the brain by binding to gp96, a unique receptor that is expressed specifically on the surface of brain endothelial cells

Resiliencia en adolescentes: el papel de la conectividad con la escuela y familia

[Abstract] The sense of connectedness with family and school is an element associated with the psychosocial development in adolescents, being a factor that can influence the way they respond against adversity and adjust to change. This study aimed to establish the predictive value of intrafamilial relationships and connectedness with school, teachers, and between students on resilience in Mexican high school adolescents. The sample consisted of 645 students (50.7% female), with an age range of 12 to 16 years old (M = 13.35, SD = 0.99), from a public high school of México. Participants answered the Intrafamilial Relations Assessment Scale, the subscales of social connectedness with school and students of the MDS3 School Climate Survey, and the revised Resilience Questionnaire for Children and Adolescents. The results indicated moderate positive associations between the study variables and resilience. The higher coefficients were found between intrafamilial relationships and resilience. In the predictive analysis, intrafamilial relationship, connectedness with school and between students, conserved its significance for predicting resilience, with family relationships maintaining the highest coefficient. Results suggest that the family environment is the main factor that shapes how adolescents cope with adversity. Limitations and practical implications are discussed. We conclude it is important to generate strategies that promote a higher adolescent connectedness with key environments for the development of protective factors such as resilience.[Resumen] El sentido de conexión con la familia y escuela es un elemento asociado con el desarrollo psicosocial de los adolescentes, siendo un factor que puede influir en su manera de responder a la adversidad y ajustarse a los cambios. Este estudio tuvo como objetivo establecer el valor predictivo de las relaciones intrafamiliares y la conexión con la escuela, los maestros y los estudiantes sobre la resiliencia en los adolescentes de secundaria. La muestra estuvo conformada por 645 estudiantes (50.7% mujeres), con un rango de edad de 12 a 16 años (M = 13.35, DT = 0.99), de una escuela secundaria pública de México. Los participantes respondieron la Escala de Evaluación de Relaciones Intrafamiliares, las subescalas de conexión social con la escuela y los estudiantes de la Encuesta de Clima Escolar MDS3 y el Cuestionario de Resiliencia para Niños y Adolescentes revisado. Los resultados indicaron correlaciones positivas moderadas entre las variables de estudio y la resiliencia, siendo la más elevada la correlación entre relaciones intrafamiliares y resiliencia. En el análisis predictivo, la relación intrafamiliar, la conexión con la escuela y entre estudiantes, conservaron la significancia para predecir la resiliencia, manteniendo las relaciones familiares los coeficientes más altos. Los resultados sugieren que el entorno familiar es el factor principal que determina cómo los adolescentes afrontan la adversidad. Se discuten las limitaciones y las implicaciones prácticas. Concluimos que es importante generar estrategias que promuevan una mayor conexión del adolescente con los entornos que influyen en el desarrollo de factores protectores como la resiliencia

SR-Like RNA-binding protein Slr1 affects Candida albicans filamentation and virulence

Candida albicans causes both mucosal and disseminated infections, and its capacity to grow as both yeast and hyphae is a key virulence factor. Hyphal formation is a type of polarized growth, and members of the SR (serine-arginine) family of RNA-binding proteins influence polarized growth of both Saccharomyces cerevisiae and Aspergillus nidulans. Therefore, we investigated whether SR-like proteins affect filamentous growth and virulence of C. albicans. BLAST searches with S. cerevisiae SR-like protein Npl3 (ScNpl3) identified two C. albicans proteins: CaNpl3, an apparent ScNpl3 ortholog, and Slr1, another SR-like RNAbinding protein with no close S. cerevisiae ortholog. Whereas ScNpl3 was critical for growth, deletion of NPL3 in C. albicans resulted in few phenotypic changes. In contrast, the slr1δ/δ mutant had a reduced growth rate in vitro, decreased filamentation, and impaired capacity to damage epithelial and endothelial cells in vitro. Mice infected intravenously with the slr1δ/δ mutant strain had significantly prolonged survival compared to that of mice infected with the wild-type or slr1δ/δ mutant complemented with SLR1 (slr1δ/δ+SLR1) strain, without a concomitant decrease in kidney fungal burden. Histopathology, however, revealed differential localization of slr1δ/δ hyphal and yeast morphologies within the kidney. Mice infected with slr1δ/δ cells also had an increased brain fungal burden, which correlated with increased invasion of brain, but not umbilical vein, endothelial cells in vitro. The enhanced brain endothelial cell invasion was likely due to the increased surface exposure of the Als3 adhesin on slr1δ/δ cells. Our results indicate that Slr1 is an SR-like protein that influences C. albicans growth, filamentation, host cell interactions, and virulence. © 2013, American Society for Microbiology

Plasma Membrane Phosphatidylinositol-4-Phosphate Is Not Necessary for Candida albicans Viability yet Is Key for Cell Wall Integrity and Systemic Infection

Phosphatidylinositol phosphates are key phospholipids with a range of regulatory roles, including membrane trafficking and cell polarity. Phosphatidylinositol-4-phosphate [PI(4)P] at the Golgi apparatus is required for the budding-to-filamentous-growth transition in the human-pathogenic fungus Candida albicans; however, the role of plasma membrane PI(4)P is unclear. We have investigated the importance of this phospholipid in C. albicans growth, stress response, and virulence by generating mutant strains with decreased levels of plasma membrane PI(4)P, via deletion of components of the PI-4-kinase complex, i.e., Efr3, Ypp1, and Stt4. The amounts of plasma membrane PI(4)P in the efr3Δ/Δ and ypp1Δ/Δ mutants were ∼60% and ∼40%, respectively, of that in the wild-type strain, whereas it was nearly undetectable in the stt4Δ/Δ mutant. All three mutants had reduced plas7ma membrane phosphatidylserine (PS). Although these mutants had normal yeast-phase growth, they were defective in filamentous growth, exhibited defects in cell wall integrity, and had an increased exposure of cell wall β(1,3)-glucan, yet they induced a range of hyphal-specific genes. In a mouse model of hematogenously disseminated candidiasis, fungal plasma membrane PI(4)P levels directly correlated with virulence; the efr3Δ/Δ mutant had wild-type virulence, the ypp1Δ/Δ mutant had attenuated virulence, and the stt4Δ/Δ mutant caused no lethality. In the mouse model of oropharyngeal candidiasis, only the ypp1Δ/Δ mutant had reduced virulence, indicating that plasma membrane PI(4)P is less important for proliferation in the oropharynx. Collectively, these results demonstrate that plasma membrane PI(4)P levels play a central role in filamentation, cell wall integrity, and virulence in C. albicans. Importance: While the PI-4-kinases Pik1 and Stt4 both produce PI(4)P, the former generates PI(4)P at the Golgi apparatus and the latter at the plasma membrane, and these two pools are functionally distinct. To address the importance of plasma membrane PI(4)P in Candida albicans, we generated deletion mutants of the three putative plasma membrane PI-4-kinase complex components and quantified the levels of plasma membrane PI(4)P in each of these strains. Our work reveals that this phosphatidylinositol phosphate is specifically critical for the yeast-to-hyphal transition, cell wall integrity, and virulence in a mouse systemic infection model. The significance of this work is in identifying a plasma membrane phospholipid that has an infection-specific role, which is attributed to the loss of plasma membrane PI(4)P resulting in β(1,3)-glucan unmasking.This work was supported by the CNRS, INSERM, Université Côte d’Azur, and ANR (ANR-11-LABX-0028-01, ANR-16-CE13-0010-01, and ANR-19-CE13-0004-01) grants, by grant R01DE026600 from the U.S. NIH, and grant SAF2017-86192 from the Spanish Ministry for Science and Innovation. R.G.-R. is a Prestige and Marie Curie Postdoctoral Fellow (funded in part by a PCOFUND- GA-2013-609102 coordinated by Campus France).S

The effects of remineralization via fluoride versus Low-Level Laser IR810 and fluoride agents on the mineralization and microhardness of bovine dental

Abstract: The objective of this study was to assess the mineralization and microhardness of bovine dental enamel surfaces treated with fluoride, tri-calcium phosphate, and infrared (IR) 810 laser irradiation. The study used 210 bovine incisors, which were divided into six groups (n = 35 in each): Group A: Untreated (control), Group B: Fluoride (Durapath-Colgate), Group C: Fluoride+Tri-calcium phosphate (Clin-Pro White-3 M), Group D: Laser IR 810 (Quantum), Group E: Fluoride+laser, and Group F: Fluoride+tri-calcium phosphate+laser). Mineralization was measured via UV-Vis spectroscopy for phosphorus and via atomic absorption spectroscopy for calcium upon demineralization and remineralization with proven agents. Microhardness (SMH) was measured after enamel remineralization. Mineral loss data showed differences between the groups before and after the mineralizing agents were placed (p < 0.05). Fluoride presented the highest remineralization tendency for both calcium and phosphate, with a Vickers microhardness of 329.8 HV0.1/11 (p < 0.05). It was observed that, if remineralization solution contained fewer minerals, the microhardness surface values were higher (r = −0.268 and −0.208; p < 0.05). This study shows that fluoride has a remineralizing effect compared with calcium triphosphate and laser IR810. This in vitro study imitated the application of different remineralizing agents and showed which one was the most efficient for treating non-cavitated injuries. This can prevent the progression of lesions in patients with white spot lesions

Factores sociales de riesgo y protección del suicidio adolescente

The phenomenon of adolescent suicide involves social and contextual issues that need to be enriched in a specialized literature, so the aim of the current research was to know the social risk and protective factors associated with this problem. A qualitative study was conducted through focus groups conformed by students, teachers and psychotherapists, chosen through a convenience sampling. Through qualitative data coding, emerged as social risk factors mass media, especially the internet, as well as been involved in a bullying situation. On the other hand, factors such as peer group, school and social context were identified as elements that can represent both risk and protective factors. It is discussed, the need of taking actions in order to develop positive interactions from a health promotion approach.El fenómeno del suicidio en adolescentes involucra elementos sociales y contextuales que necesitan enriquecerse en la literatura especializada, por lo que el objetivo de la presente investigación fue conocer los factores sociales de riesgo y protección asociados a dicha problemática. Para ello se condujo un estudio cualitativo de tipo fenomenológico mediante grupos focales conformados por estudiantes, profesores y terapeutas, elegidos por medio de un muestreo por conveniencia. A través de la codificación de datos cualitativos emergieron como factores sociales de riesgo los medios de comunicación, especialmente el internet, así como el encontrarse envuelto en una situación de bullying. Por su parte, factores como el grupo de pares, la escuela y el contexto social se observaron como elementos que pueden representar tanto riesgo como protección. Se discute la necesidad de emprender acciones en favor del desarrollo de interacciones positivas desde un enfoque de promoción de la salud

The Fungal Exopolysaccharide Galactosaminogalactan Mediates Virulence by Enhancing Resistance to Neutrophil Extracellular Traps

Of the over 250 Aspergillus species, Aspergillus fumigatus accounts for up to 80% of invasive human infections. A. fumigatus produces galactosaminogalactan (GAG), an exopolysaccharide composed of galactose and N-acetyl-galactosamine (GalNAc) that mediates adherence and is required for full virulence. Less pathogenic Aspergillus species were found to produce GAG with a lower GalNAc content than A. fumigatus and expressed minimal amounts of cell wall-bound GAG. Increasing the GalNAc content of GAG of the minimally pathogenic A. nidulans, either through overexpression of the A. nidulans epimerase UgeB or by heterologous expression of the A. fumigatus epimerase Uge3 increased the amount of cell wall bound GAG, augmented adherence in vitro and enhanced virulence in corticosteroid-treated mice to levels similar to A. fumigatus. The enhanced virulence of the overexpression strain of A. nidulans was associated with increased resistance to NADPH oxidase-dependent neutrophil extracellular traps (NETs) in vitro, and was not observed in neutropenic mice or mice deficient in NADPH-oxidase that are unable to form NETs. Collectively, these data suggest that cell wall-bound GAG enhances virulence through mediating resistance to NETs