The effects of a social skills training program on aggressive behaviour with institutionalized juvenile delinquents

Situation-specific behavioural deficits have been found to account for at least some of the aggressive behaviours displayed by juvenile delinquents. The present investigation undertook to evaluate the effectiveness of a social skills training package in achieving a reduction in delinquents’ aggressive behaviours. Such a training program offers one procedure through which appropriate responding in social situations can be taught. Previous research had suggested that aggressive behaviour was a relevant target behaviour for this population. -- Twenty-four students from a residential training center for juvenile delinquents served as subjects for this investigation. They ranged in age from 14-16 years (mean=15.2). The sex distribution of the subjects reflected their respective proportions in the center's population. -- Three measures of verbal and physical aggression were employed to assess the efficacy of the training program: (a) the frequency of fines and warnings issued by the staff members for verbal and physical aggressiveness, (b) in vivo observations of aggressive behaviour during a free-time period, and (c) ratings of social skills in response to provocative situations presented on audiotape. -- The students were divided into a treatment group and a control group equated in terms of sex-distribution and pre-treatment level of aggression. -- The students in the training group met weekly for eight weeks. During these meetings, the concepts of assertion, aggression and non-assertion were first introduced. A variety of skills for assertively responding to provocations were applied to job interviews and interpersonal problem situations identified by the students. The social skills training included modelling, rehearsal and feedback, coaching, and homework assignments. -- The students in the control group were given no treatment in addition to the normal program of the institution. -- On all the measures of aggressiveness collected, the training group did not differ significantly from the control group at either the pre-treatment or the post-treatment assessments. Furthermore, the behaviour of the training group did not change significantly over the course of the investigation. -- These results indicate that the social skills training package, as presently applied, was not successful in altering the amount of aggressive behaviour displayed by the students. -- Difficulties in obtaining accurate data on the students' aggressive behaviour and their implications for conclusions from the study are discussed

Cystatin F is a cathepsin C-directed protease inhibitor regulated by proteolysis

Cystatins are a family of naturally occurring cysteine protease inhibitors, yet the target proteases and biological processes they regulate are poorly understood. Cystatin F is expressed selectively in immune cells and is the only cystatin to be synthesised as an inactive disulphide-linked dimeric precursor. Here, we show that a major target of cystatin F in different immune cell types is the aminopeptidase cathepsin C, which regulates the activation of effector serine proteases in T cells, natural killer cells, neutrophils and mast cells. Surprisingly, recombinant cystatin F was unable to inhibit cathepsin C in vitro even though overexpression of cystatin F suppressed cellular cathepsin C activity. We predicted, using structural models, that an N-terminal processing event would be necessary before cystatin F can engage cathepsin C and we show that the intracellular form of cystatin F indeed has a precise N-terminal truncation that creates a cathepsin C inhibitor. Thus, cystatin F is a latent protease inhibitor itself regulated by proteolysis in the endocytic pathway. By targeting cathepsin C, it may regulate diverse immune cell effector functions