Cajal´s achievements in the field of the development of dendritic arbors

13 páginas, 7 figuras.In 1909, Cajal published an up-dated version in French (Cajal, 1909-1911) of his main work Texture of the Nervous System of Man and Vertebrates (Cajal, 1899-1904), considered the most important book devoted to the nervous system. Owing that last year was the centenary of this publication, we decided to produce an article focused on Cajal´s description of the morphological changes that dendritic trees undergo during development. We will emphasize his brilliant hypotheses explaining the modelling of dendritic trees (the neurotropic hypothesis and the role of neuronal activity in the patterning of the dendritic trees), and the status of this topic in present day Neuroscience. Here, we will show original photographs taken from a selected collection of Cajal´s slides housed in the Cajal Museum (Instituto Cajal, CSIC, Madrid, Spain) illustrating the principal changes in neuronal morphology at different stages of development of the spinal cord, cerebellum and cerebral cortex. We will also discuss Cajal’s initial proposals regarding the influence of neurotropic substances (chemotactic hypothesis) and neural activity in the modelling of the dendritic tree, as well as the evidence that later confirmed these theories.P. GL. is supported by the Fundación Caixa Galicia. This study was supported by grants from Spain´s Ministry of Science and Innovation (SAF2007- 60010) and the Instituto de Salud Carlos III (RETICS, RENEVAS, RD06/ 0026/1001).Peer reviewe

CB2 cannabinoid receptor activation promotes colon cancer progression via AKT/GSK3β signaling pathway

The pharmacological activation of the cannabinoid receptor type 2, CB2, has been shown to elicit anti-tumoral mechanisms in different cancer types. However, little is known about its endogenous role in tumor pathophysiology, and different studies have attributed pro-tumorigenic properties to this receptor. In a previous work, we showed that CB2 expression is a poor prognostic factor in colon cancer patients. Here we report that activation of CB2 with low doses of specific agonists induce cell proliferation and favor the acquisition of aggressive molecular features in colon cancer cells. We show that sub-micromolar concentrations of CB2-specific agonists, JWH-133 and HU-308, promote an increase in cell proliferation rate through the activation of AKT/PKB pathway in colon cancer in vitro and in vivo. AKT activation promotes GSK3β inhibition and thus, a more aggressive cell phenotype with the subsequent elevation of SNAIL levels, E-cadherin degradation and β-catenin delocalization from cell membrane. Taken together, our data show that CB2 activation with sub-micromolar doses of agonists, which could be more similar to endogenous levels of cannabinoids, promote colon cancer progression, implicating that CB2 could have a pro-tumorigenic endogenous role in colon cancerThis work was supported by grants from Fondo de Investigaciones Sanitarias (ISCIII-PI10/00879 to JMG; Plan Nacional de I+D+I 2008-2011, FEDER funds co-financed), Red Temática de Investigación Cooperativa en Cáncer (ISCIII-RETIC RD12/0036/0041; Plan Estatal de I+D+I 2013-2016, FEDER funds cofinanced). JMG and PM were supported by ISCIII CP08/00217 and JR14/0018 contracts, respectively. EMM was recipient of ISCIII PFIS PhD studentship (FI11/00696) (Plan Nacional de I+D+I 2008-2011, FEDER funds co-financed); AMR was recipient of PhD contract from Department of Medical Oncology of H.U. Puerta de Hierro; VC was recipient of attending physician contract in Medical Oncology Department from H.U. Puerta de Hierro; MP was supported by Universidad Autónoma de Madrid (UAM) with Full Professor contrac

Estilos de liderança em centros educacionais de Heredia: um estudo comparativo entre a administração e corpo docente

Leadership is a fundamental feature of institutions in general and the field of education in particular. The leadership style can directly influence the organizational climate of the institutions, promoting a good performance in the administrative and teaching staff, as well as in the students. A quantitative methodology was used in the present research, with an ex-post-facto and cross-sectional design, applying the Multifactor Leadership Questionnaire (MLQ) to a stratified probabilistic sample of 125 managers and 584 teachers of public schools of the Regional Directorate of Education of Heredia. The main outcomes show high scores in the transformational and transactional leadership styles and low in the laissez-faire style. Likewise, significant differences have been detected between the self-perception of headteachers and teachers concerning these styles. Aspects related to tasks, beliefs, self-confidence, problem-solving set off with different perceptions between both groups of professionals. This dissociation from the same reality can interfere in the management carried out by school principals regarding common goal and objectives fulfillment. The legitimation of the educational community towards the leadership exercised by headteachers is a key element for effective educational organization management. El liderazgo es una característica fundamental en las instituciones en general y en el ámbito educativo en particular. El estilo de liderazgo puede influir directamente en el clima organizacional de las instituciones, promoviendo un buen desempeño tanto del personal docente y administrativo como del colectivo estudiantil. La presente investigación responde a una metodología cuantitativa, con un diseño ex post facto y transversal, con la aplicación del cuestionario Multifactor Leadership Questionnaire (MLQ) a una muestra probabilística estratificada de 125 personas directivas y 584 docentes de centros educativos públicos de la Dirección Regional de Educación de Heredia. Los principales resultados muestran altas puntuaciones en los estilos de liderazgo transformacional y transaccional y bajas en el estilo laissez faire. Igualmente, se han detectado diferencias significativas entre la autopercepción de personas directoras y docentes en relación con los estilos mencionados. Aspectos relacionados con las tareas, creencias, confianza, formas de enfrentar los problemas, se destacan con percepciones diferentes entre ambos grupos de profesionales. La disociación sobre una misma realidad puede interferir en la gestión que realiza la persona directora para el cumplimiento de metas y objetivos comunes. La legitimación de la comunidad educativa hacia el liderazgo ejercido por el personal directivo es elemento clave para una gestión efectiva de la organización educativa. A liderança é uma característica fundamental nas instituições em geral e no campo educacional em particular; o estilo de liderança pode influenciar diretamente o clima organizacional das instituições, promovendo um bom desempenho tanto do pessoal docente, administrativo com do corpo estudantil. Esta pesquisa responde a uma metodologia quantitativa, com um desenho ex post facto e transversal, aplicando o Questionário de Liderança Multifatorial (MLQ - Multifactor Leadership Questionnaire) a uma amostra probabilística estratificada de 125 pessoas diretoras e 584 docentes de centros educacionais públicos da Direção Regional de Educação de Heredia. Os principais resultados mostram pontuações altas nos estilos de liderança transformacional e transacional e baixas no estilo laissez faire. Também foram detectadas diferenças significativas entre a autopercepção dos diretores e docentes em relação a estes estilos. Aspectos relacionados a tarefas, crenças, confiança, formas de enfrentar problemas, destacam-se com percepções diferentes entres os dois grupos de profissionais. Esta dissociação da mesma realidade pode interferir na gestão que realiza a pessoa diretora no cumprimento das metas e objetivos comuns. A legitimação da comunidade educativa em relação à liderança exercida pelo pessoal diretor é um elemento chave para uma gestão eficaz da organização educativa.&nbsp

Matrimonio igualitario

In Colombia, they have developed normative precepts in order to legitimize equal or same-sex marriage. However, there is still much legal and social sphere, to consider whether the samesex marriage is consistent with the constitutional provisions and the recognition that every human being can freely choose their marital status, decide clearly when and who you want to live together and raise a family. In the present article the subject of marriage of same-sex couples in Colombia is addressed, and conceptualizes about current regulations, in light of the rulings of the Constitutional Court. In the end, succinctly the conclusions of the investigation is established.En Colombia, se han desarrollado preceptos normativos en el propósito de legitimar el matrimonio igualitario o de personas del mismo sexo. Sin embargo, aún no existe claridad tanto jurídica como en ámbito de lo social, de considerar si el matrimonio entre personas del mismo sexo está acorde con los preceptos constitucionales y en el reconocimiento de que todo ser humano puede elegir libremente su estado civil, decidir cuándo y con quien quiere vivir unido y formar una familia. En el presenta artículo se aborda el tema del matrimonio de personas del mismo sexo en Colombia, y se conceptualiza acerca de la normatividad vigente, a la luz de los pronunciamientos de la Corte Constitucional. Al final, de manera sucinta, se establecen las conclusiones derivadas de la investigación

Aspectos conceptuales sobre la inteligencia afectiva y su fomento a través de la lectura en la escuela

The affective trend continues being the forgotten subject in the curriculum. The new milenium school cannot give up the challenge of educating in harmony, from the respect to individual differences, all  the aspects of one's personality. There are not any widely accepted propositions yet that can lead the pedagogical praxis wich is launched to cultívate such dimension, and the obstacles wich fiad iniciatives of this kind aren't just few. In this article the concept of affective intelligence is analized as to a mixture of racional and emotional processes that has to receive educative attention. Here are some practical recommendations targeted at educators and emphasizes the value of reading as a resource for the development of affective intelligence. En este artículo se profundiza en el concepto de “inteligencia afectiva”, en sus implicaciones educativas y en su cultivo a través de la lectura. Aunque cada vez se reconoce más la trascendencia de la educación de la afectividad, siguen siendo insuficientes los esfuerzos por desarrollar programas formativos sistemáticos y rigurosos. En este trabajo se ofrecen recomendaciones prácticas dirigidas a educadores y se destaca el valor de la lectura como recurso psicopedagógico para desarrollar la inteligencia afectiva

Analysis of notch effect in load bearing capacity, apparent fracture toughness and fracture micromechanisms of ferritic–pearlitic steels

This paper presents the analysis of the notch effect in two ferritc–pearlitic steels: S275JR and S355J2. The research is based on the development and analysis of an experimental programme composed of 336 CT specimens, combining 6 different notch radii, and testing temperatures from the lower shelf up to the upper shelf of the two materials. The notch effect is analysed through the evolution of both the load bearing capacity and the apparent fracture toughness, and also through the relation between these two variables and the failure micromechanisms. The results reveal a clear notch effect in both materials. In the case of the load bearing capacity, this notch effect has its maximum at lower shelf temperatures. The notch effect in the apparent fracture presents a maximum at the lower temperatures of the ductileto-brittle transition zone. Finally, the Scanning Electron Microscopy fractographies have justified the previous observations

Melatonin modulation of crosstalk among malignant epithelial, endothelial and adipose cells in breast cancer (Review)

Melatonin, the main secretory product of the pineal gland, is an oncostatic agent that reduces the growth and development of various types of tumors, particularly mammary tumors whose growth is dependent on estrogens. Previous in vivo and in vitro studies point to the hypothesis that melatonin interplays with estrogen signaling pathways at three different levels: i) an indirect mechanism, by interfering with the hypothalamic‑pituitary‑reproductive axis in such way that the level of plasma estrogens synthesized by the gonadal glands are downregulated; ii) a direct mechanism of the pineal gland at the cell cancer level, disrupting the activation of estradiol receptors, therefore behaving as a selective estrogen receptor modulator; and iii) by regulating the enzymes involved in the biosynthesis of estrogens in other tissues, thus behaving as a selective estrogen enzyme modulator. The intratumoral metabolism and synthesis of estrogens, as a result of the interactions of various enzymes, is more important than blood uptake to maintain mammary gland estrogen levels in menopausal females. Additionally, estrogens are considered to play an important role in the pathogenesis and development of hormone‑dependent breast carcinoma. Paracrine interactions among malignant epithelial cells and proximal adipose and endothelial cells, through cytokines and growth factors produced by breast tumor cells, modulate estrogen production at the mammary tumor level and, as a consequence, the genesis and development of mammary tumors. The aim of the present review is to summarize the recent findings describing the mechanisms by which melatonin is able to modulate the crosstalk among malignant epithelial, endothelial and adipose cells in breast cancer

Piglet innate immune response to Streptococcus suis colonization is modulated by the virulence of the strain

Streptococcus suis is a zoonotic pathogen of swine involved in arthritis, polyserositis, and meningitis. Colonization of piglets by S. suis is very common and occurs early in life. The clinical outcome of infection is influenced by the virulence of the S. suis strains and the immunity of the animals. Here, the role of innate immunity was studied in cesarean-derived colostrum-deprived piglets inoculated intranasally with either virulent S. suis strain 10 (S10) or non-virulent S. suis strain T15. Colonization of the inoculated piglets was confirmed at the end of the study by PCR and immunohistochemistry. Fever (≥40.5 °C) was more prevalent in piglets inoculated with S10 compared to T15 at 4 h after inoculation. During the 3 days of monitoring, no other major clinical signs were detected. Accordingly, only small changes in transcription of genes associated with the antibacterial innate immune response were observed at systemic sites, with S10 inducing an earlier response than T15 in blood. Local inflammatory response to the inoculation, evaluated by transcriptional analysis of selected genes in nasal swabs, was more sustained in piglets inoculated with the virulent S10, as demonstrated by transcription of inflammation-related genes, such as IL1B, IL1A, and IRF7. In contrast, most of the gene expression changes in trachea, lungs, and associated lymph nodes were observed in response to the non-virulent T15 strain. Thus, S. suis colonization in the absence of systemic infection induces an innate immune response in piglets that appears to be related to the virulence potential of the colonizing strain

Escuelas para la justicia social: experiencias de liderazgo en dos centros educativos costarricenses

El liderazgo para la justicia social es un tema que ha cobrado relevancia en los espacios de diálogo vinculados a temas educativos, en muchos contextos alrededor del mundo y Costa Rica no es la excepción. El objetivo de este estudio es el análisis en relación con esta temática, así como el aporte de ideas para los educadores en formación y en ejercicio; igualmente, para las personas que dirigen el rumbo en materia de políticas educativas del país. Desde un enfoque cualitativo, se implementa el protocolo de entrevista de la Red Internacional de Desarrollo de Liderazgo (ISLDN), que surge como parte de las reflexiones en la Convención de la University Council for Educational Administration (UCEA) en el 2008, el cual está conformado por cinco preguntas. Los sujetos de análisis son dos directivos escolares, concretamente del nivel de preescolar público y de una unidad pedagógica privada. Los resultados sugieren un estilo de liderazgo democrático con algunas características de transformacional, centrados en aspectos de la justicia social como reconocimiento y capacidades de las personas. Además, se hallan coincidencias, en ambos casos, con los aportes teóricos revisados basados en las cuatro categorías de justicia social: económica, cultural, asociativa y para el desarrollo