[The influence of social stress on the reinforcing effect of ecstasy under the conditioned place preference paradigm: the role played by age, dose and type of stress]. / Influencia del estres social en el efecto reforzante del extasis bajo el paradigma de condicionamiento de preferencia de lugar: papel de la edad, la dosis y el tipo de estres.

INTRODUCTION: Addiction to drugs is a chronic illness with severe repercussions for those that consume them and to date has no known cure. Psychostimulants, such as ecstasy, are the most widely consumed illegal drugs among adolescents and young adults. AIMS: To describe and to analyse the different variables that can influence the effects of social stress and the reinforcing properties of ecstasy. Likewise, it also seeks to evaluate whether the effects of social stress on conditioned place preference (induced by ecstasy) are similar to those deriving from other psychostimulants, such as cocaine. DEVELOPMENT: Social defeat evaluated in the short term has an effect only on adult animals by diminishing sensitivity to the conditioned reinforcing effects of ecstasy. Conversely, long-term social stress increases the reinforcing effects of this drug in adolescent and adult animals. The dose of ecstasy employed has little influence on the effects of social defeat on conditioned place preference. In comparison to the effects of social stress on the reinforcing properties of cocaine, a different effect is only observed when defeat is evaluated in the short term. CONCLUSIONS: Different variables modulate the reinforcing effects of ecstasy, such as the age of the animals, the dose employed or exposure to stress. It is essential to study these variables in order to determine the neurobiological and environmental vulnerability factors that can have an influence on the development of addiction to ecstasy.

TITLE: Influencia del estres social en el efecto reforzante del extasis bajo el paradigma de condicionamiento de preferencia de lugar: papel de la edad, la dosis y el tipo de estres.Introduccion. La adiccion a las drogas es una enfermedad cronica con graves repercusiones para sus consumidores y que hasta el momento no tiene curacion. Los psicoestimulantes, como el extasis, son las drogas ilegales mas consumidas, tanto por los adolescentes como por los adultos jovenes. Objetivos. Describir y analizar diferentes variables que pueden influir en los efectos del estres social y las propiedades reforzantes del extasis. Asimismo, se pretende evaluar si los efectos del estres social sobre el condicionamiento de preferencia de lugar (inducido por el extasis) son similares a los que ejercen otros psicoestimulantes, como la cocaina. Desarrollo. La derrota social evaluada a corto plazo solo ejerce un efecto en animales adultos, disminuyendo la sensibilidad a los efectos reforzantes condicionados del extasis. Por el contrario, el estres social a largo plazo incrementa los efectos reforzantes de esta droga en animales adolescentes y adultos. La dosis de extasis utilizada ejerce una escasa influencia en los efectos de la derrota social sobre el condicionamiento de preferencia de lugar. En comparacion con los efectos del estres social sobre las propiedades reforzantes de la cocaina, unicamente se observa un efecto diferente cuando la derrota es evaluada a corto plazo. Conclusiones. Existen diferentes variables que modulan los efectos reforzantes del extasis, como la edad de los animales, la dosis utilizada o la exposicion al estres. El estudio de todas estas variables es esencial para determinar los factores de vulnerabilidad neurobiologicos y ambientales que pueden influir en el desarrollo de dependencia al extasis.

Leucine aminopeptidase is an immunodominant antigen of Fasciola hepatica excretory and secretory products in human infections.

The liver fluke Fasciola hepatica parasitizes humans and ruminant livestock worldwide, and it is now being considered a reemerging zoonotic disease, especially in areas in which it is endemic, such as South America. This study investigates the immune response to excretory and secretory products produced by F. hepatica in a group of patients from the Peruvian Altiplano, where the disease is highly endemic. Using a proteomic approach and immunoblotting techniques, we have identified the enzymes leucine aminopeptidase (LAP) and phosphoenolpyruvate carboxykinase as immunodominant antigens recognized by sera from fasciolosis patients. An indirect enzyme-linked immunosorbent assay using recombinant LAP as the antigen was developed to check sera from individuals of this region. Our results demonstrate that LAP produces a specific and strong reaction, suggesting its potential use in the serologic diagnosis of F. hepatica infections in humans.