Membrane vesicles, current state-of-the-art: emerging role of extracellular vesicles

Release of membrane vesicles, a process conserved in both prokaryotes and eukaryotes, represents an evolutionary link, and suggests essential functions of a dynamic extracellular vesicular compartment (including exosomes, microparticles or microvesicles and apoptotic bodies). Compelling evidence supports the significance of this compartment in a broad range of physiological and pathological processes. However, classification of membrane vesicles, protocols of their isolation and detection, molecular details of vesicular release, clearance and biological functions are still under intense investigation. Here, we give a comprehensive overview of extracellular vesicles. After discussing the technical pitfalls and potential artifacts of the rapidly emerging field, we compare results from meta-analyses of published proteomic studies on membrane vesicles. We also summarize clinical implications of membrane vesicles. Lessons from this compartment challenge current paradigms concerning the mechanisms of intercellular communication and immune regulation. Furthermore, its clinical implementation may open new perspectives in translational medicine both in diagnostics and therapy

Achievement Place: experiments in self-government with pre-delinquents

One of the goals of many treatment programs for pre-delinquent youths is the development of the skills involved in the democratic decision-making process. At Achievement Place, one aspect of the treatment program is a semi-self-government system whereby the seven pre-delinquent youths can democratically establish many of their own rules of behavior, monitor their peers' behavior to detect violations of their rules, and conduct a “trial” to determine a rule violator's guilt or innocence, and to determine the consequences for a youth who violates a rule. Two experiments were carried out to determine the role of some of the procedures in the boys' participation in the self-government system. Experiment I showed that more boys participated in the discussion of consequences for a rule violation when they had complete responsibility for setting the consequence during the trials than when the teaching-parents set the consequence for each rule violation before the trial. An analysis of the rule violations in this experiment indicated that the boys in Achievement Place reported more of the rule violations that resulted in trials than reported by the teaching-parents or school personnel. The boys reported rule violations that occurred in the community and school as well as at Achievement Place, including most of the serious rule violations that came to the attention of the teaching-parents. In Experiment II, the results indicated that more trials were called when the teaching-parents were responsible for calling trials on rule violations reported by the peers than when the boys were responsible for calling trials. When the youths earned points for calling trials the average number of trials per day increased, but more trivial rule violations were reported. These results suggest that aspects of the democratic decision-making process in a small group of pre-delinquents can be studied and variables that affect participation can be identified and evaluated

Achievement Place: the reliability of self-reporting and peer-reporting and their effects on behavior

The reliability of the boys reporting their own behavior of their peers was measured in two experiments at Achievement Place, a community based, family style, behavior modification program for delinquents based on a token (point) economy. The results of these experiments indicated that; (a) the boys were not “naturally” reliable observers, (b) the reliability of peer-reporting could be improved by providing training on the behavioral definitions and by making points contingent on agreement between each boy's peer-report and an independent adult observers' report, (c) the reliability of self-reporting could be improved by making points contingent on agreement between the self-report and the trained peer's report, and (d) giving self-reports and peer-reports did not produce a systematic effect on the boys' room-cleaning behavior as measured by an independent observer

Achievement Place: development of the elected manager system

A series of experiments was carried out to compare several administrative systems at Achievement Place, a family style behavior modification program for pre-delinquent boys. One aspect of the motivation system at Achievement Place was the token economy in which the youths could earn or lose points that could be exchanged for privileges. Several arrangements for assigning routine tasks and for providing token consequences for task performance were compared for their effectiveness in accomplishing the tasks and for their preference by the boys. The independent variables studied included: (1) individually assigned tasks versus group assigned tasks; (2) consequences for individual performance versus consequences for group performance; (3) a peer managership that could be earned by the highest bidder versus a peer managership that could be determined democratically by the peers. The results suggested that among those systems studied the system that best met the criteria of effectiveness and preference involved a democratically elected peer manager who had the authority both to give and to take away points for his peers' performances

The training and validation of youth-preferred social behaviors of child-care personnel

This research sought to identify, train, and validate social behaviors preferred by youths to be used by youth-care personnel (called teaching-parents). With training, consistent increases in seven preferred behaviors were observed for the six teaching-parent trainees. These behaviors included offering to help, “getting to the point”, giving reasons why a behavior is important to a youth, providing descriptions of alternative behaviors, positive feedback, smiling, and positive motivational incentives (i.e., points for task mastery exchanged for tangible reinforcers). Increases in these behaviors correlated with increases in the youths' ratings of the quality of the trainees' interactions. Posttraining levels of preferred social behavior and youth ratings for trainees also compared favorably with levels for successful professional teaching-parents. These results suggest that teaching-parents can be successfully trained to interact with youths in ways that are preferred by the youths