RESUMEN
The three-dimensional architecture of the pancreatic islet is integral to beta cell function, but the process of islet formation remains poorly understood due to the difficulties of imaging internal organs with cellular resolution. Within transparent zebrafish larvae, the developing pancreas is relatively superficial and thus amenable to live imaging approaches. We performed in vivo time-lapse and longitudinal imaging studies to follow islet development, visualizing both naturally occurring islet cells and cells arising with an accelerated timecourse following an induction approach. These studies revealed previously unappreciated fine dynamic protrusions projecting between neighboring and distant endocrine cells. Using pharmacological compound and toxin interference approaches, and single-cell analysis of morphology and cell dynamics, we determined that endocrine cell motility is regulated by phosphoinositide 3-kinase (PI3K) and G-protein-coupled receptor (GPCR) signaling. Linking cell dynamics to islet formation, perturbation of protrusion formation disrupted endocrine cell coalescence, and correlated with decreased islet cell differentiation. These studies identified novel cell behaviors contributing to islet morphogenesis, and suggest a model in which dynamic exploratory filopodia establish cell-cell contacts that subsequently promote cell clustering.
Asunto(s)
Islotes Pancreáticos/crecimiento & desarrollo , Islotes Pancreáticos/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas de Pez Cebra/metabolismo , Pez Cebra/crecimiento & desarrollo , Pez Cebra/metabolismo , Citoesqueleto de Actina/metabolismo , Animales , Animales Modificados Genéticamente , Agregación Celular , Movimiento Celular , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/metabolismo , Islotes Pancreáticos/citología , Queratina-18/genética , Queratina-18/metabolismo , Organogénesis , Inhibidores de las Quinasa Fosfoinosítidos-3 , Seudópodos/metabolismo , Seudópodos/ultraestructura , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Análisis de la Célula Individual , Pez Cebra/genética , Proteínas de Pez Cebra/antagonistas & inhibidores , Proteínas de Pez Cebra/genética , Proteína de Unión al GTP rac1/antagonistas & inhibidores , Proteína de Unión al GTP rac1/metabolismoRESUMEN
The Affective Neuroscience Personality Scales have been designed to provide a personality assessment tool based on six distinct affective systems. The six neural systems involved were labeled PLAY, SEEK, CARE, FEAR, ANGER and SADNESS. Spirituality has been integrated into the questionnaire as a seventh dimension because, in opinion of Panksepp and his colleagues is one of the most interesting human emotion. The aim of the present paper was introduce the validation of the Spanish version of Affective Neuroscience Personality Scales and their first psychometric results in a sample of 411 college students. Participants completed the Spanish version of ANPS, just as a personality scale of five factors (NEO-FFI-R), and the Scales of Positive and Negative Affect (PANAS). The factor structure obtained and psychometric properties of the scales indicate that the Spanish version of the scales provides an effective tool to measure the seven dimensions of personality proposal in the original questionnaire.
Asunto(s)
Afecto/fisiología , Comparación Transcultural , Emociones/fisiología , Neurociencias , Determinación de la Personalidad/estadística & datos numéricos , Adolescente , Adulto , Encéfalo/fisiología , Femenino , Humanos , Masculino , Inventario de Personalidad/estadística & datos numéricos , Psicometría/estadística & datos numéricos , Valores de Referencia , Reproducibilidad de los Resultados , Factores Sexuales , España , Espiritualidad , Traducción , Adulto JovenRESUMEN
A shape sensitive, variational approach for the matching of surfaces considered as thin elastic shells is investigated. The elasticity functional to be minimized takes into account two different types of nonlinear energies: a membrane energy measuring the rate of tangential distortion when deforming the reference shell into the template shell, and a bending energy measuring the bending under the deformation in terms of the change of the shape operators from the undeformed into the deformed configuration. The variational method applies to surfaces described as level sets. It is mathematically well-posed, and an existence proof of an optimal matching deformation is given. The variational model is implemented using a finite element discretization combined with a narrow band approach on an efficient hierarchical grid structure. For the optimization, a regularized nonlinear conjugate gradient scheme and a cascadic multilevel strategy are used. The features of the proposed approach are studied for synthetic test cases and a collection of geometry processing examples.
RESUMEN
Se realizó un estudio prospectivo, retrospectivo y comparativo en 47 pacientes con fracturas intertrocantéricas de fémur tratadas con P.F.N. y D.H.S. en el Hospital Central de Maracay durante los años 2001 al 2004 para establecer cual de los dos métodos ha reportado: menos complicaciones intraoperatorias, una una deambulación temprana y consiguió consolidación de la fractura en menos tiempo. Hubo incidencia del 70,2 por ciento en mujeres, el promedio de edad fue 72 años, el 93,6 por ciento fueron debidas a las caídas a sus pies. El tipo de fractura más frecuente fue la 3,1-A2. Los pacientes tratados con P.F.N. presentaron menos tiempo quirúrgico, alcanzaron la marcha asistida e independiente más rápida y un tiempo de consolidación menos que el grupo tratado con D.H.S. Concluimos que el P.F.N. presenta mayores ventajas que el D.H.S. en el tratamiento de estas fracturas con mejores resultados.