Multi-site study of the Childhood Autism Rating Scale (CARS) in five clinical groups of young children.

This study examined several questions pertaining to the Childhood Autism Rating Scale (CARS) in a sample of 274 preschool children (aged 2-6 years) clinically diagnosed as falling in one of five groups: Autistic Disorder, PDD-NOS, MR, Delayed, and Other. In addition to diagnosis and the CARS, all children were given standardized cognitive and adaptive behavior measures. Results indicated high concordance between the CARS and clinical diagnosis using DSM-IV (including excellent sensitivity and specificity). There was a moderate negative correlation of CARS scores and developmental level (both cognitive and adaptive), indicating significant shared variance. There were significant and sensible differences in mean CARS score for different diagnostic groups, including a substantial difference between the Autistic Disorder and PDD-NOS groups.

Brief report: the Vineland Adaptive Behavior Scales in young children with autism spectrum disorders at different cognitive levels.

Vineland Adaptive Behavior Scales (VABS) data were examined in a large sample of young children with ASD (n = 290) of varying cognitive levels. IQ was higher than VABS composite score among high functioning children only; the opposite pattern was found in lower IQ subgroups. Profile analysis of VABS domains across cognitive levels demonstrated different profiles in different subgroups. A characteristic "autism profile" was found for most subgroups for Age Equivalents but not Standard Scores. In a small set of matched pairs (n = 28) of children with autism versus MR, significantly different profiles were found, with Socialization and Communication lower in autism, but no differences were found between matched pairs of children with autism and PDD-NOS (n = 48). Correlations between age, cognitive level, and adaptive level were also reported, and regression analyses indicated that autism severity accounts for a modest amount of unique variance in Socialization and Daily Living Skills.

Myofibrillogenesis in skeletal muscle cells.

How are myofibrils assembled in skeletal muscles? The current authors present evidence that myofibrils assemble through a three-step model: premyofibrils to nascent myofibrils to mature myofibrils. This three-step sequence was based initially on studies of living and fixed cultured cells from cardiac muscle. Data from avian primary muscle cells and from a transgenic skeletal mouse cell line indicate that a premyofibril model for myofibrillogenesis also holds for skeletal muscle cells. Premyofibrils are characterized by minisarcomeres bounded by Z-bodies composed of the muscle isoform of alpha-actinin. Actin filaments are connected to these Z-bodies and to the mini-A-bands composed of nonmuscle myosin II filaments. Nascent myofibrils are formed when premyofibrils align and are modified by the addition of titin and muscle myosin II filaments. Mature myofibrils result when nonmuscle myosin II is eliminated from the myofibrils and the alpha-actinin rich Z-bodies fuse as the distance between them increases from 0.5 microm in premyofibrils to 2 to 2.5 microm in the mature myofibrils.