Estudio de la biocompatibilidad in vitro de polimeros metacrílicos derivados de pirrolidona-ina

Este estudio analiza la biocompatibilidad de nuevos biomateriales a base de hidrogeles metacrílicos como el poli-[metacrilato de 2-etil-(2-pirrolidona)] (PEPM) y la poli-[metacrilato de 2-etil-(2-pirrolidina)], en comparación con referentes comerciales tales como la poli-(vinil pirrolidona) (PVP) y la poli-(N-N´-dimetilacrilamida) (PDMA). Se utilizaron propiedades bioquímicas, mediante los ensayos de MTT y Alamar Blue, para conocer el efecto de citotoxicidad y proliferación en cultivo de fibroblastos (células VERO), sobre los biomateriales metacrílicos. Adicionalmente, por microscopía óptica y electrónica fueron analizados el grado de adhesión, morfología, muerte celular, proliferación, contracción celular, etc. Además se estudiaron las relaciones entre citotoxicidad y estructura química. En el MTT y en el análisis óptico se obtuvo baja citotoxicidad para PEPM y PVP, media en PEPyM y alta en PDMA. En el Alamar Blue y SEM se produjo una media proliferación-adhesión en PEPM y PEPyM, alta en PVP y muerte celular en PDMA. Sus apropiadas características físico-químicas y su aceptable grado de biocompatibilidad les hacen buenos candidatos en aplicaciones tales como lentes de contacto, sistemas de liberación de fármacos e ingeniería de tejidos.This study analyzed biocompatibility of new biomaterials based on the methacrylic hydrogels derived poly-[2-ethyl-(2-pyrrolidone) methacrylate] (PEPM) and poly-[2-ethyl-(2-pyrrolidine) methacrylate] (PEPyM), in comparison with references such as commercial poly-(vinyl pyrrolidone) (PVP) and poly-(N, N-dimethylacrylamide) (PDMA). The biochemical properties were used to know citotoxicity and proliferation effect over fibroblast culture (VERO cells) in contact with the methacrylic biomaterials, using MTT and Alamar Blue assays. Additionally, were analyzed adhesion grade, morphology, death cell presence, proliferation, cell contraction, etc, by optical and scanning electronic microscopy (SEM). The relationships between their chemical structures and cytotoxicity were studied. In MTT and optical analysis, low cytotoxicity was found for PEPM and PVP, medium in the case of PEPyM, and high for PDMA. In Alamar Blue and SEM, were produced a medium proliferation and adhesion rate for PEPM and PEPyM, high in PVP, and cellular death for PDMA. Their appropriates physico-chemical characteristics and approval biocompatibility grade make them good candidates in applications such as contact lenses, drug release systems and tissue engineering

Food and Feeding of Most Abundant Fish Species in Flemish Cap

Food and feeding of the 15 fish species taken by bottom trawl from Flemish Cap Bank in summer during the period 2001-2003 were analysed. The stomach contents of 17 773 fish were collected in depths from 83 to 730 m. In general, the feeding intensity was high in all the species with a maximum value for Gadus morhua (96.3%) and minimum for Lycodes reticulatus (35.0%). The prey spectrum was width, with a total of 134 items for all the stomachs analysed. In frequency of occurrence, the crustaceans were the most important preys (FO = 80.4%), while in volume (V = 39.4%) they were less significant than fishes (V = 43.5%). The main prey group in frequency of occurrence were Hyperiidea, Copepoda, Pandalus borealis and Chaetognata. The niche width index was also calculated for these species

Feeding Habits and Diet Overlap of Skates (Amblyraja radiata, A. hyperborea, Bathyraja spinicauda, Malacoraja senta and Rajella fyllae) in the North Atlantic

The contents of 5061 stomach of five skate species -thorny (Amblyraja radiata), Arctic (A. hyperborea), spinytail (Bathyraja spinicauda), smooth (Malacoraja senta) and round skates (Rajella fyllae) obtained from Spanish Bottom Trawl Research Surveys in northwest and northeast Atlantic (NAFO, Divisions 3NO and Div. 3M; ICES, Div. IIb) in the period 1996-2005 were analyzed to study the feeding intensity and food habits. Feeding intensity was high in all skate species and areas, slightly higher in Div. IIb, showing a general trend to decrease according to the predator size increase. Importance of prey was based in weight percentage. The main prey groups for thorny and Arctic skates were Pisces and Crustacea, but the importance of each group and prey species changed with area. Pisces has turn out to be the dominant prey taxa for spinytail skate in Div. 3NO and 3M. Crustacea have been the dominant prey group for smooth skate. Round skate has changed its main prey group in each area, but polychaetes have been prominent in Div. 3NO. Predation on fishing processed remnant was important for Arctic skate. Predation on several species of commercial importance was mainly relevant in Div. 3M. Intra-specific diet overlap showed a different pattern varying with skate species and area. Inter-specific diet overlap reached its highest level in the Arctic area. Thorny skate showed a high diet overlap with the majority of the skate species studied in the NAFO Area, and round skate did not show diet overlap with other skate species in Div. 3NO. Thorny skate appear as dominant predator in NAFO Div. 3NO

TUP1-mediated filamentation in Candida albicans leads to inability to colonize the mouse gut.

AIM To investigate the role of Candida albicans TUP1-mediated filamentation in the colonization of the mice gut. MATERIALS & METHODS We used molecular genetics to generate a strain where filamentation is regulated by altering the expression of the TUP1 gene with tetracyclines. RESULTS The colonization rates reached with the TUP1-RFP strain were lower compared with wild-type strain and completely absent after induction of filamentation. No differences in the susceptibility to bile salts nor in the adhesion to the mouse intestine epithelium were observed. CONCLUSION Blockage of C. albicans in a filamentous form impedes gut cell colonization in the mouse

Implementation of a CRISPR-Based System for Gene Regulation in Candida albicans.

Clustered regularly interspaced short palindromic repeat (CRISPR) methodology is not only an efficient tool in gene editing but also an attractive platform to facilitate DNA, RNA, and protein interactions. We describe here the implementation of a CRISPR-based system to regulate expression in the clinically important yeast By fusing an allele of Cas9 devoid of nuclease activity to a transcriptional repressor (Nrg1) or activator (Gal4), we were able to show specific repression or activation of the tester gene , encoding the cytosolic catalase. We generated strains where a 1.6-kbp upstream regulatory region of controls the expression of the green fluorescent protein (GFP) and demonstrated the functionality of the constructs by quantitative PCR (qPCR), flow cytometry, and analysis of sensitivity/resistance to hydrogen peroxide. Activation and repression were strongly dependent on the position of the complex in this regulatory region. We also improved transcriptional activation using an RNA scaffolding strategy to allow interaction of inactive variants of Cas9 (dCas9) with the RNA binding protein MCP (monocyte chemoattractant protein) fused to the VP64 activator. The strategy shown here may facilitate the analysis of complex regulatory traits in this fungal pathogen. CRISPR technology is a new and efficient way to edit genomes, but it is also an appealing way to regulate gene expression. We have implemented CRISPR as a gene expression platform in using fusions between a Cas9 inactive enzyme and specific repressors or activators and demonstrated its functionality. This will allow future manipulation of complex virulence pathways in this important fungal pathogen

The Glyoxylate Cycle Is Involved in White-Opaque Switching in Candida albicans

Candida albicans is a commensal yeast that inhabits the gastrointestinal tract of humans. The master regulator of the white-opaque transition WOR1 has been implicated in the adaptation to this commensal status. A proteomic analysis of cells overexpressing this transcription factor (WOR1OE) suggested an altered metabolism of carbon sources and a phenotypic analysis confirmed this alteration. The WOR1OE cells are deficient in using trehalose and xylose and are unable to use 2C sources, which is consistent with a reduction in the amount of Icl1, the isocitrate lyase enzyme. The icl1∆/∆ mutants overexpressing WOR1 are deficient in the production of phloxine B positive cells, a main characteristic of opaque cells, a phenotype also observed in mating type hemizygous mtla1∆ icl1∆/∆ cells, suggesting the involvement of Icl1 in the adaptation to the commensal state. In fact, icl1∆/∆ cells have reduced fitness in mouse gastrointestinal tract as compared with essentially isogenic heterozygous ICL1/icl1∆, but overproduction of WOR1 in an icl1∆/∆ mutant does not restore fitness. These results implicate the glyoxylate shunt in the adaptation to commensalism of C. albicans by mechanisms that are partially independent of WOR1

Construcción teórica de la asesoría psicopedagógica

La formación del Licenciado en Educación. Pedagogía-Psicología como asesor psicopedagógico demanda la apropiación teórica de la asesoría psicopedagógica a directivos y docentes como modo de actuación profesional, en correspondencia con el objeto de la profesión y las esferas de actuación. En la comprensión del rol de asesor psicopedagógico se manifiestan insuficiencias que limitan la configuración teórico-metodológica de este proceso profesional. En esta dirección y como respuesta a esta problemática se propone, desde un enfoque interdisciplinar, la lógica de la construcción de la asesoría psicopedagógica en pos de favorecer el dominio del modo de actuación a partir de la relación académica, laboral e investigativo. Este trabajo es resultado de investigaciones doctorales de los autores. Se emplea desde una perspectiva sistémica métodos teóricos: analítico-sintético, histórico-lógico y empíricos: observación, encuesta, entrevista y análisis documental. Los resultados expresan la dialéctica integradora del proceso de formación para la asesoría psicopedagógica y su aplicación contextualizada en situaciones educativas. PALABRAS CLAVE: construcción; asesoría psicopedagógica; modo de actuación profesional. THEORETICAL CONSTRUCTION OF PSYCHOPEDAGOGICAL ADVICE ABSTRACT The formation of the Bachelor of Education. Pedagogy-Psychology as a psychopedagogical advisor demands the theoretical appropriation of psychopedagogical advice to managers and teachers as a mode of professional action, in correspondence with the object of the profession and the spheres of action. In the understanding of the role of psychopedagogical advisor, there are inadequacies that limit the theoretical-methodological configuration of this professional process. In this direction and in response to this problem, from an interdisciplinary approach, the logic of the construction of psycho-pedagogical advice is proposed in order to favor the mastery of the mode of action based on the academic, labor and research relationship. This work is been of the authors' doctoral investigations. Theoretical methods are used from a systemic perspective: analytical-synthetic, historical-logical and empirical: observation, survey, interview and documentary analysis. The results express the integrative dialectic of the training process for psychopedagogical advice and its contextualized application in educational situations. KEYWORDS: construction; psychopedagogical advice service; way of professional behavior

CONFIGURACIÓN DE LOS APRENDIZAJES PROFESIONALES PARA LA ASESORÍA PSICOPEDAGÓGICA DESDE EL ENFOQUE INTERDISCIPLINAR

RESUMEN El proceso de formación inicial del Licenciado en Educación. Pedagogía-Psicología demanda la aprehensión de la asesoría psicopedagógica a directivos y docentes como modo de actuación profesional, en correspondencia con el objeto de la profesión y las esferas de actuación. En la evaluación de la comprensión y ejecución del rol de asesor psicopedagógico se detectan insuficiencias en el proceso formativo que limitan la configuración teórico-metodológica de este proceso profesional. En esta dirección y como respuesta a esta problemática se propone, desde un enfoque interdisciplinar, la configuración de los aprendizajes profesionales para la asesoría psicopedagógica en pos de favorecer el dominio del modo de actuación a partir de la relación académica, laboral e investigativo. Se emplea desde una perspectiva sistémica métodos teóricos: analítico-sintético, histórico-lógico y empíricos: observación, encuesta, entrevista y análisis documental. Los resultados expresan la dialéctica integradora del proceso de formación de la asesoría psicopedagógica y su aplicación contextualizada en situaciones educativas. PALABRAS CLAVE: Configuración; aprendizajes profesionales; Asesoría psicopedagógica CONFIGURATION OF PROFESSIONAL LEARNING FOR PSYCHOPEDAGOGIC ADVISORY FROM THE INTERDISCIPLINARY APPROACH ABSTRACT The initial formation process for the Bachelor of Education. Pedagogy-Psychology demands the apprehension of psychopedagogical advisory to managers and teachers as a way of professional acting, in correspondence with the object of the profession and the spheres of action. In the evaluation of the understanding and execution of the role of psycho-pedagogical advisor, inadequacies are detected in the training process that limit the theoretical-methodological configuration of this professional process. In this direction and as an answer to this problem it is proposed, from an interdisciplinary focus, the configuration of professional learning for psychopedagogical advisory in order to favor the domain of the action mode from the academic, laboral and research relationship. Theoretical methods are used from a systemic perspective: analytical-synthetic, historical-logical and empirical: observation, survey, interview and documentary analysis. The results express the integrating dialectic of the process of formation of psychopedagogical counseling and its contextualized application in educational situations. KEYWORDS: Configuration; professional learning; psychopedagogical advisory

Identification of Clinical Isolates of Candida albicans with Increased Fitness in Colonization of the Murine Gut

The commensal and opportunistic pathogen Candida albicans is an important cause of fungal diseases in humans, with the gastrointestinal tract being an important reservoir for its infections. The study of the mechanisms promoting the C. albicans commensal state has attracted considerable attention over the last few years, and several studies have focused on the identification of the intestinal human mycobiota and the characterization of Candida genes involved in its establishment as a commensal. In this work, we have barcoded 114 clinical C. albicans isolates to identify strains with an enhanced fitness in a murine gastrointestinal commensalism model. The 114 barcoded clinical isolates were pooled in four groups of 28 to 30 strains that were inoculated by gavage in mice previously treated with antibacterial therapy. Eight strains that either exhibited higher colonization load and/or remained in the gut after antibiotic removal were selected. The phenotypic analysis of these strains compared to an RFP-tagged SC5314 wild type strain did not reveal any specific trait associated with its increased colonization; all strains were able to filament and six of the eight strains displayed invasive growth on Spider medium. Analysis of one of these strains, CaORAL3, revealed that although mice required previous bacterial microbiota reduction with antibiotics to be able to be colonized, removal of this procedure could take place the same day (or even before) Candida inoculation. This strain was able to colonize the intestine of mice already colonized with Candida without antibiotic treatment in co-housing experiments. CaORAL3 was also able to be established as a commensal in mice previously colonized by another (CaHG43) or the same (CaORAL3) C. albicans strain. Therefore, we have identified C. albicans isolates that display higher colonization load than the standard strain SC5314 which will surely facilitate the analysis of the factors that regulate fungal colonization

Non-canonical Activities of Hog1 Control Sensitivity of Candida albicans to Killer Toxins From Debaryomyces hansenii

Certain yeasts secrete peptides known as killer toxins or mycocins with a deleterious effect on sensitive yeasts or filamentous fungi, a common phenomenon in environmental species. In a recent work, different () strains isolated from a wide variety of cheeses were identified as producing killer toxins active against and . We have analyzed the killer activity of these toxins in mutants defective in MAPK signaling pathways and found that the lack of the MAPK Hog1 (but not Cek1 or Mkc1) renders cells hypersensitive to mycocins while mutants lacking other upstream elements of the pathway behave as the wild type strain. Point mutations in the phosphorylation site (T174A-176F) or in the kinase domain (K52R) of gene showed that both activities were relevant for the survival of to killer toxins. Moreover, Hog1 phosphorylation was also required to sense and adapt to osmotic and oxidative stress while the kinase activity was somehow dispensable. Although the addition of supernatant from the killer toxin- producing 242 strain (-242) induced a slight intracellular increase in Reactive Oxygen Species (ROS), overexpression of cytosolic catalase did not protect against this mycocin. This supernatant induced an increase in intracellular glycerol concentration suggesting that this toxin triggers an osmotic stress. We also provide evidence of a correlation between sensitivity to -242 killer toxin and resistance to Congo red, suggesting cell wall specific alterations in sensitive strains