Neglect as a deficit determined by an imbalance between multiple spatial representations.

A previous study on neglect suggested that at least two hand parameters are crucial in producing an amelioration of neglect: the hand (left or right) and the spatial position of the hand (left or right). The improvement observed in perceiving left targets when the left hand acts in the left space can be due either to proprioceptive or to visual cuing. The stimulated left hand located in the left space may act as a powerful visual cue for the enhancement of the left visuo-spatial representation, in the same way as any other visual stimulus presented in the periphery of the visual field.

Derangement of non-specific immunity in Down syndrome subjects: low leukocyte chemiluminescence activity after phagocytic activation.

Metabolic activation of peripheral blood leukocytes (chemiluminescence) from 27 children with Down syndrome (DS) and 23 age and sex-matched control children after phagocytic stimulation by opsonized zymosan particles was investigated through a chemiluminescence assay. Using autologous plasma or serum as opsonizing media, phagocytic activity of circulating leukocytes was significantly decreased in DS subjects. A further decrease of phagocytic activity was found in neutrophils from DS children, when normal heterologous plasma or sera were used.

Enhancing effect of lithium and potassium ions on lectin-induced lymphocyte proliferation in aging and Down's syndrome subjects.

The effect of different concentrations of LiCl or KCl (0.6-20 meq/liter) on PHA-stimulated lymphocytes from young, old, and Down's syndrome subjects was studied. LiCl showed a dramatic enhancing effect on [3H]thymidine incorporation induced by a suboptimal dose of PHA in old subjects and Down's syndrome patients.

Defective self-recognition in subjects of far-advanced age.

The immunocompetence of 22 subjects aged 85-104 years (mean 90 +/- 1 years) was studied and compared to 21 young subjects aged 19-37 years (mean 30 +/- 1 years). The absolute lymphocyte number and the percentage of T and B lymphocytes in the peripheral blood was similar in the two groups. A marked decrease in phytohemagglutinin response of T-enriched lymphocytes from old subjects was observed.