Analysis of alternative signaling pathways of endoderm induction of human embryonic stem cells identifies context specific differences

Background: Lineage specific differentiation of human embryonic stem cells (hESCs) is largely mediated by specific growth factors and extracellular matrix molecules. Growth factors initiate a cascade of signals which control gene transcription and cell fate specification. There is a lot of interest in inducing hESCs to an endoderm fate which serves as a pathway towards more functional cell types like the pancreatic cells. Research over the past decade has established several robust pathways for deriving endoderm from hESCs, with the capability of further maturation. However, in our experience, the functional maturity of these endoderm derivatives, specifically to pancreatic lineage, largely depends on specific pathway of endoderm induction. Hence it will be of interest to understand the underlying mechanism mediating such induction and how it is translated to further maturation. In this work we analyze the regulatory interactions mediating different pathways of endoderm induction by identifying co-regulated transcription factors.Results: hESCs were induced towards endoderm using activin A and 4 different growth factors (FGF2 (F), BMP4 (B), PI3KI (P), and WNT3A (W)) and their combinations thereof, resulting in 15 total experimental conditions. At the end of differentiation each condition was analyzed by qRT-PCR for 12 relevant endoderm related transcription factors (TFs). As a first approach, we used hierarchical clustering to identify which growth factor combinations favor up-regulation of different genes. In the next step we identified sets of co-regulated transcription factors using a biclustering algorithm. The high variability of experimental data was addressed by integrating the biclustering formulation with bootstrap re-sampling to identify robust networks of co-regulated transcription factors. Our results show that the transition from early to late endoderm is favored by FGF2 as well as WNT3A treatments under high activin. However, induction of late endoderm markers is relatively favored by WNT3A under high activin.Conclusions: Use of FGF2, WNT3A or PI3K inhibition with high activin A may serve well in definitive endoderm induction followed by WNT3A specific signaling to direct the definitive endoderm into late endodermal lineages. Other combinations, though still feasible for endoderm induction, appear less promising for pancreatic endoderm specification in our experiments. © 2012 Mathew et al.; licensee BioMed Central Ltd

Composición y estructura fitoperifitica de la cuenca media y baja del río Cesar, departamento Cesar-Colombia

Objective. The composition and structure of Fitoperifiton the middle and lower basin of the Cesar River and its relationship to the physical and chemical variables were characterized. Materials and methods. Sampling was conducted between February to September 2011. Samples available natural substrates (rocks, sediment and plant debris) were collected, physical and chemical variables in situ and in vivo were measured. Results. 110 Morphospecies classes represented in 9 and 22 orders were found, the Bacillariophyceae had the highest density with 48% (45 species), Cyanophyceae with 35% (18 species), followed by Fragilariophyceae with 7% (9 species), Chlorophyceae 2 % (11 species), Euglenophyceae with 2% (5 species) and Trebouxiophyceae Coscinodiscophyceae with 4% and 1% (respectively 4 and 3 species) and finally with Ulvophyceae 0.00005% (1 species). The most representative Anabaena sp.1 Morphospecies (136.70 Cel/cm2), Oscillatoria Vaucher (129.80 Cel/cm2) and Oscillatoria sp.1 (90.20 Cel/cm2). an analysis of principal components (ACP) where segmentation of some sections of the Cesar River and fitoperifiton was observed to characterize the stations for their peculiarities was made excessive growth of species in areas where they are wastewater discharges high were observed organic matter such as blue-green algae. Conclusions. The Cyanophyceae were negatively associated with oxygen according to the ACC. It was evident that the sector Puente Salguero is characterized by high concentration of organic phosphorus, plus the Fitoperifiton the Cesar River, identified this sector as the most critical point of organic contamination of the system and its influence stations downstream.Objetivo. Se caracterizó la composición y estructura del Fitoperifiton de la cuenca media y baja del río Cesar y su relación con las variables físicas y químicas. Materiales y métodos. Los muestreos se realizaron entre febrero-septiembre de 2011. Se recolectaron muestras de sustratos naturales disponibles (rocas, sedimento y restos vegetales), se midieron variables físicas y químicas In situ e In vivo. Resultados. Se encontraron 110 morfoespecies representadas en 9 clases y 22 órdenes, las Bacillariophyceae presentaron la mayor densidad con un 48% (45 especies), Cyanophyceae con 35% (18 especies), seguida de Fragilariophyceae con 7% (9 especies), Chlorophyceae con 2% (11 especies), Euglenophyceae con 2% (5 especies), Coscinodiscophyceae y Trebouxiophyceae con 4% y 1% (4 y 3 especies respectivamente) y por ultimo Ulvophyceae con 0.00005% (1 especie). Las morfoespecies más representativas Anabaena sp.1 (136.70 Cel/cm2), Oscillatoria vaucher (129.80 Cel/cm2) y Oscillatoria sp.1 (90.20 Cel/cm2). Se realizó un análisis de Componentes Principales (ACP) donde se observó una sectorización de algunos tramos del río Cesar y del fitoperifiton, para caracterizar las estaciones por sus particularidades se observaron crecimiento excesivos de especies en zonas donde se encuentran vertimientos de aguas residuales con alto contenido de materia orgánica como las algas verde-azules. Conclusiones. Las Cyanophyceae se asociaron negativamente con el oxígeno según el ACC. Se evidencio que el sector de Puente Salguero es caracterizado por alta concentración de fósforo orgánico, además el Fitoperifiton del río Cesar, identifico este sector como el punto más crítico de contaminación orgánica del sistema y sus influencia estaciones río abajo

El Porfiriato

1 archivo PDF (229 páginas)Debate sobre el Porfiriato desde una perspectiva crítica y analítica de la historia y el diseño para mostrar lo más actual de la reflexión histórica y que, al mismo tiempo, sea útil para la generación de nuevos conocimientos, propósito fundamental para la formación de futuras generaciones de estudiosos e investigadores sobre la historia nacional y la historia del diseño

A Multiple-Choice Maze-like Spatial Navigation Task for Humans Implemented in a Real-Space, Multipurpose Circular Arena.

Spatial navigation is a key aspect of human behavior and it is still not completely understood. A number of experimental approaches exist, although most of the published data in the last decades have relied on virtual maze on-screen simulation or not-completely freely moving 3D devices. Some interesting recent developments, such as circular mazes, have contributed to analyze critical aspects of freely moving human spatial navigation in real space, although dedicated protocols only allow for simple approaches. Here, we have developed both specifically designed and home-assembled hardware equipment, and a customized protocol for spatial navigation evaluation in freely moving humans in a real space circular arena. The spatial navigation protocol poses an imitation of a real-space multiple-choice path maze with cul-de-sac and instances of non-linear movement. We have compared the results of this system to those of a number of validated, both virtual and real, spatial navigation tests in a group of participants. The system composed by hardware, the test protocol, and dedicated measure analysis designed in our laboratory allows us to evaluate human spatial navigation in a complex maze with a small and portable structure, yielding a highly flexible, adaptable, and versatile access to information about the subjects’ spatial navigation abilities.P.M. was funded by a predoctoral fellowship (FPI) grant, PRE2020/093032, from the Ministerio de Ciencia e Innovación; E.C. was funded by a predoctoral fellowship (FPI) grant, BES-2017/080415, from the Ministerio de Economía y Competitividad; P.T. was funded by a predoctoral fellowship (FPU) grant, 18/00069, from the Ministerio de Universidades. This research received no other external specific funding

Interesantes imágenes de fosfato de cobre obtenidas en un microscopio electrónico de barrido

Actualmente la tecnología avanza muy rápido y conocer como son los objetos pequeños y muy pequeños ya no es complicado. Se cuenta con herramientas como los últimos microscopios electrónicos de barrido para poder observarlos a detalle, la estructura cristalina puede elucidarse a través de la difracción de rayos X. El material cristalino de fosfato de Cobre tri-hidratado caracterizado por difracción de rayos X de polvos (DRX-P) es afectado por el medio ambiente (su entorno) perdiendo su cristalinidad (pasando a la fase amorfa), las micrografías de barrido en esta transición muestran formas caprichosas de nanoflores o nanolechugas rizadas formadas de nanolaminas dispuestas en forma radial. El tamaño de las partículas es aproximadamente de 80 a 90 nm. Este estudio demuestra que una síntesis tradicional de obtención de fosfato (II) de Cobre trihidratado a partir de soluciones de sulfato de Cobre y fosfato de sodio es un método adecuado para la preparación de nanopartículas con interesantes morfologías.Nowadays, the technology progresses quickly, and to know how small and very small objects are, is no longer complicated. There are tools such as the modern scanning electron microscopes to watch them in detail; crystal structure can be seen through X-ray diffraction. The tri-hydrated copper phosphate crystalline material characterized by X-ray powder diffraction (XRD-P) is affected by the environment (its surroundings) losing its crystallinity (passing to the amorphous phase). The scanning electron microscopy photographs show capricious forms of nanoflowers or nanolettuces formed from nanolayers placed radially. The particles size is approximately 80 to 90 nm. This study shows that to obtain phosphates by traditional synthesis of tri-hydrated copper from copper(II) sulfate and sodium phosphate is an adequate method for the nanoparticles preparation with interesting morphologies

Validity of Virtual Reality Body Exposure to Elicit Fear of Gaining Weight, Body Anxiety and Body-Related Attentional Bias in Patients with Anorexia Nervosa

Fear of gaining weight (FGW), body image disturbances, associated anxiety and body-related attentional bias are the core symptoms of anorexia nervosa (AN) and play critical roles in its development and maintenance. The aim of the current study is to evaluate the usefulness of virtual reality-based body exposure software for the assessment of important body-related cognitive and emotional responses in AN. Thirty female patients with AN, one of them subclinical, and 43 healthy college women, 25 with low body dissatisfaction (BD) and 18 with high BD, owned a virtual body that had their silhouette and body mass index. Full-body illusion (FBI) over the virtual body was induced using both visuo-motor and visuo-tactile stimulation. Once the FBI was induced, the FBI itself, FGW, body anxiety and body-related attentional bias toward weight-related and non-weight-related body areas were assessed. One-way analyses of covariance (ANCOVA), controlling for age, showed that AN patients reported higher FGW, body anxiety and body-related attentional bias than healthy controls. Unexpectedly, patients with AN reported significantly lower FBI levels than healthy participants. Finally, Pearson correlations showed significant relationships between visual analog scales and body-related attentional bias measures, compared to other eating disorder measures. These results provide evidence about the usefulness of virtual reality-based body exposure to elicit FGW and other body-related disturbances in AN patients. Thus, it may be a suitable intervention for reducing these emotional responses and for easing weight recovery

A Multiple-Choice Maze-like Spatial Navigation Task for Humans Implemented in a Real-Space, Multipurpose Circular Arena

Spatial navigation is a key aspect of human behavior and it is still not completely understood. A number of experimental approaches exist, although most of the published data in the last decades have relied on virtual maze on-screen simulation or not-completely freely moving 3D devices. Some interesting recent developments, such as circular mazes, have contributed to analyze critical aspects of freely moving human spatial navigation in real space, although dedicated protocols only allow for simple approaches. Here, we have developed both specifically designed and home-assembled hardware equipment, and a customized protocol for spatial navigation evaluation in freely moving humans in a real space circular arena. The spatial navigation protocol poses an imitation of a real-space multiple-choice path maze with cul-de-sac and instances of non-linear movement. We have compared the results of this system to those of a number of validated, both virtual and real, spatial navigation tests in a group of participants. The system composed by hardware, the test protocol, and dedicated measure analysis designed in our laboratory allows us to evaluate human spatial navigation in a complex maze with a small and portable structure, yielding a highly flexible, adaptable, and versatile access to information about the subjects’ spatial navigation abilities

AN-VR-BE. A randomized controlled trial for reducing fear of gaining weight and other eating disorder symptoms in anorexia nervosa through virtual reality-based body exposure

In vivo body exposure therapy is considered an effective and suitable intervention to help patients with anorexia nervosa (AN) reduce their body image disturbances (BIDs). However, these interventions have notable limitations and cannot effectively reproduce certain fears usually found in AN, such as the fear of gaining weight (FGW). The latest developments in virtual reality (VR) technology and embodiment-based procedures could overcome these limitations and allow AN patients to confront their FGW and BIDs. This study aimed to provide further evidence of the efficacy of an enhanced (by means of embodiment) VR-based body exposure therapy for the treatment of AN. Thirty-five AN patients (16 in the experimental group, 19 in the control group) participated in the study. FGW, BIDs, and other body-related and ED measures were assessed before and after the intervention and three months later. The experimental group received treatment as usual (TAU) and five additional sessions of VR-based body exposure therapy, while the control group received only TAU. After the intervention, ED symptoms were clearly reduced in both groups, with most of the changes being more noticeable in the experimental group. Specifically, after the intervention and at follow-up, significant group differences were found in the FGW and BIDs, with the experimental group showing significantly lower values than the control group. The current study provides new insights and encouraging findings in the field of exposure-based therapies in AN. VR technology might improve research and clinical practice in AN by providing new tools to help patients confront their core fears (i.e., food- or weight-related cues) and improve their emotional, cognitive, and behavioral responses to their body image

A transcriptomic analysis of gene expression in the venom gland of the snake Bothrops alternatus (urutu)

<p>Abstract</p> <p>Background</p> <p>The genus <it>Bothrops </it>is widespread throughout Central and South America and is the principal cause of snakebite in these regions. Transcriptomic and proteomic studies have examined the venom composition of several species in this genus, but many others remain to be studied. In this work, we used a transcriptomic approach to examine the venom gland genes of <it>Bothrops alternatus</it>, a clinically important species found in southeastern and southern Brazil, Uruguay, northern Argentina and eastern Paraguay.</p> <p>Results</p> <p>A cDNA library of 5,350 expressed sequence tags (ESTs) was produced and assembled into 838 contigs and 4512 singletons. BLAST searches of relevant databases showed 30% hits and 70% no-hits, with toxin-related transcripts accounting for 23% and 78% of the total transcripts and hits, respectively. Gene ontology analysis identified non-toxin genes related to general metabolism, transcription and translation, processing and sorting, (polypeptide) degradation, structural functions and cell regulation. The major groups of toxin transcripts identified were metalloproteinases (81%), bradykinin-potentiating peptides/C-type natriuretic peptides (8.8%), phospholipases A₂(5.6%), serine proteinases (1.9%) and C-type lectins (1.5%). Metalloproteinases were almost exclusively type PIII proteins, with few type PII and no type PI proteins. Phospholipases A₂were essentially acidic; no basic PLA₂were detected. Minor toxin transcripts were related to L-amino acid oxidase, cysteine-rich secretory proteins, dipeptidylpeptidase IV, hyaluronidase, three-finger toxins and ohanin. Two non-toxic proteins, thioredoxin and double-specificity phosphatase Dusp6, showed high sequence identity to similar proteins from other snakes. In addition to the above features, single-nucleotide polymorphisms, microsatellites, transposable elements and inverted repeats that could contribute to toxin diversity were observed.</p> <p>Conclusions</p> <p><it>Bothrops alternatus </it>venom gland contains the major toxin classes described for other <it>Bothrops </it>venoms based on trancriptomic and proteomic studies. The predominance of type PIII metalloproteinases agrees with the well-known hemorrhagic activity of this venom, whereas the lower content of serine proteases and C-type lectins could contribute to less marked coagulopathy following envenoming by this species. The lack of basic PLA₂agrees with the lower myotoxicity of this venom compared to other <it>Bothrops </it>species with these toxins. Together, these results contribute to our understanding of the physiopathology of envenoming by this species.</p