Social competence and conduct problems in young children: issues in assessment.

Examined the differences in various facets of social competence in 2 groups of young children (ages 4-7 years)--a clinic-referred group of aggressive children (N = 60) diagnosed with oppositional defiant disorder or conduct problems and a matched comparison group of typically developing children (N = 60). Four aspects of social competence were assessed: social information processing, actual observations of conflict management skills and social play interactions during peer interactions, positive social interactions with mothers and fathers at home, and teacher reports of social competence. The social information processing assessed included problem-solving skills (hypothetical skills as demonstrated on a social problem-solving test), self-perceptions (child's awareness of his or her own social self and feelings of loneliness), perceptions of others (attributions), and perceptions of others' attitudes toward oneself. To determine the construct validity of various means of assessing child social competence, we correlated children's social information processing measures with parent and teacher reports of social adjustment and with actual observations of interactions during peer play and at home with parents. Results comparing the 2 groups suggest that young children with conduct problems have deficits in their social information processing awareness or interpretation of social cues--they overestimate their own social competence and misattribute hostile intent to others. Tests of cognitive problem solving and observations of peer play interactions indicated that the children with conduct problems had significantly fewer positive problem-solving strategies and positive social skills, more negative conflict management strategies, and delayed play skills with peers than the comparison children. Correlation analyses indicated significant correlations between children's negative attributions and the ratio of positive to negative problem-solving strategies with observations of peer play interactions.

The occurrence of a mutant dimerizable histone H5 in Japanese quail erythrocytes.

An allelic variant of linker histone H5 has been found in the erythrocytes of Japanese quail (Coturnix japonica) descended from a small group of feral birds captured on the island of Hawaii. This variant spontaneously forms protein dimers in vitro in the absence of reducing agents. That this depends upon the introduction of a sulfhydryl group (presumably because of a cysteine substitution) is indicated by its reaction with 2-nitro-5-thiocyanobenzoate and by its fluorescence after reaction with 4-aminosulfonyl-7-fluoro-2,1,3-benzoxadiazole. This is the first reported example of cysteine in a vertebrate linker histone and offers a specific reactive site for structural studies. A homozygous line for this form of H5 is being developed.

Short term bioassay of cigarettes containing Cytrel tobacco supplement.

The toxicity of smoke from cigarettes containing tobacco, Cytrel tobacco supplement, or mixtures of the 2 materials, was investigated using 6 short term test methods. The tests used were rat trachea organ culture and mouse skin thickening tests, which may provide information on carcinogenicity, a ciliatoxicity test, an alveolar macrophage viability test, a haemolysis assay and a thiol inactivation test to provide measures of irritant and cytotoxic effects. In each case a response to the smoke from cigarettes containing tobacco alone was detected, while the magnitude of this response declined as the proportion of tobacco supplement in the blend increased. The least response was found with smoke from cigarettes containing Cytrel tobacco supplement alone.