ABSTRACT
Ramón y Cajal proposed 100 years ago that memory formation requires the growth of nerve cell processes. One-half century later, Hebb suggested that growth of presynaptic axons and postsynaptic dendrites consequent to coactivity in these synaptic elements was essential for such information storage. In the past 25 years, candidate growth genes have been implicated in learning processes, but it has not been demonstrated that they in fact enhance them. Here, we show that genetic overexpression of the growth-associated protein GAP-43, the axonal protein kinase C substrate, dramatically enhanced learning and long-term potentiation in transgenic mice. If the overexpressed GAP-43 was mutated by a Ser --> Ala substitution to preclude its phosphorylation by protein kinase C, then no learning enhancement was found. These findings provide evidence that a growth-related gene regulates learning and memory and suggest an unheralded target, the GAP-43 phosphorylation site, for enhancing cognitive ability.
Subject(s)
Behavior, Animal/physiology , GAP-43 Protein/physiology , Animals , Gene Expression/physiology , Learning/physiology , Mice , Mice, TransgenicABSTRACT
The effect of an electromagnetic field on the healing of skin ulcers of venous origin in humans has been investigated in a double-blind study. Forty-four patients have been admitted to the study; one-half were exposed to active stimulators (experimental group) and the remaining to dummy stimulators (control group). The stimulation was scheduled to last a maximum of 90 days. The success rate was significantly higher in the experimental group both at day 90 (p less than 0.02) and in the follow-up period (p less than 0.005). The data suggest that the effect of the electromagnetic field lasts even when the stimulation is over. No ulcers worsened in the experimental group, while four worsened in the control group. Twenty-five percent of the patients in the experimental group and 50% in the control group experienced recurrence of the ulcer. It is concluded that stimulation with an electromagnetic field is a useful adjunctive therapy in the management of these patients.
Subject(s)
Electromagnetic Fields , Electromagnetic Phenomena , Skin Ulcer/therapy , Aged , Double-Blind Method , Female , Humans , Male , Skin Ulcer/etiology , Skin Ulcer/physiopathology , Venous Insufficiency/complications , Wound Healing/physiologyABSTRACT
Hemorheological measurements were made in 8 stable chronic haemodialysis patients observed in conventional acetate dialysis (AD) with Cuprophan membrane and then in biofiltration (BF) with PAN AN69S membrane. Blood viscosity diminished at the beginning, both during BF and AD, reaching pre-dialytic values again at the end of treatment. Blood and erythrocyte filtration increased after 20 min in AD and throughout the session in BF. Preliminary results suggest an improvement of hemorheological parameters during dialytic treatment, more notable in BF than in AD.
