Relationships among age, sex, and lateral dominance for 3- to 6-year-old children performing unilateral stance.

To assess influence of age, sex, and lateral dominance on children's unilateral stance, from 6 Houston area preschools and day-care centers, 121 subjects were randomly selected and judged by teachers as normal 3- to 6-yr-old children. The children were tested for eye, hand, and foot preference and were then classified on over-all dominance. Maximal duration of unilateral stance, or up to 60 sec., was tested on each foot. Means over age groups show progressive increase in duration of unilateral stance with increasing age. No sex differences were found. A stepwise multiple correlation-regression showed stance on the nondominant foot and age as the only significant variables in stance on the dominant foot. Clinically, this study can help in evaluating children for neurodevelopmental disorders.

Intracellular electrophysiological alterations in canine cardiac conducting tissue induced by aprindine and lignocaine.

The effects of aprindine and lignocaine (lidocaine USP) were compared on intracellularly recorded potentials from normal canine conducting tisues. Only aprindine produced marked depression of the maximum rate of rise (Vmax) of action potentials elicited at normal cycle lengths (1000 ms). Both compounds, however, produced enhanced depression of Vmax at short cycle lengths or at short S1-S2 coupling intervals at normal membrane resting potential. Both lignocaine and aprindine shorten the action potential duration (APD) and effective refractory period (ERP) but increase the EPR/APD ratio. These effects are easily reversible upon perfusion with drug-free solution only in the case of lignocaine.