1 In this study, we examined the effects of crude venom from the spider Parawixia bistriata on glutamate and GABA uptake into synaptosomes prepared from rat cerebral cortex. Addition of venom to cortical synaptosomes stimulated glutamate uptake and inhibited GABA uptake in a concentration-dependent manner. 2 The venom was fractionated using reverse-phase high-performance liquid chromatography on a preparative column. The fraction that retained glutamate uptake-stimulating activity was further purified on a reverse-phase analytical column followed by ion-exchange chromatography. 3 The active fraction, referred to as PbTx1.2.3, stimulated glutamate uptake in synaptosomes without changing the K M value, and did not affect GABA uptake. Additional experiments showed that the enhancement of glutamate uptake by PbTx1.2.3 occurs when ionotropic glutamate receptors or voltage-gated sodium and calcium channels are completely inhibited or when GABA receptors and potassium channels are activated, indicating that the compound may have a direct action on the transporters. 4 In an experimental model for glaucoma in which rat retinas are subjected to ischemia followed by reperfusion, PbTx1.2.3 protected neurons from excitotoxic death in both outer and inner nuclear layers, and ganglion cell layers. 5 This active spider venom component may serve as a basis for designing therapeutic drugs that increase glutamate clearance and limit neurodegeneration.

The major contribution of this work is the isolation of a neuroprotective compound referred to as 2-amino-5-ureidopentanamide (FrPbAII) (M r ϭ 174) from Parawixia bistriata spider venom and an investigation of its mode of action. FrPbAII inhibits synaptosomal GABA uptake in a dose-dependent manner and probably does not act on Na ϩ , K ϩ , and Ca 2ϩ channels, GABA B receptors, or ␥-aminobutyrate:␣-ketoglutarate aminotransferase enzyme; therefore, it is not directly dependent on these structures for its action. Direct increase of GABA release and reverse transport are also ruled out as mechanisms of FrPbAII activities as well as unspecific actions on pore membrane formation. Moreover, FrPbAII is selective for GABA and glycine transporters, having slight or no effect on monoamines or glutamate transporters. According to our experimental glaucoma data in rat retina, FrPbAII is able to cross the blood-retina barrier and promote effective protection of retinal layers submitted to ischemic conditions. These studies are of relevance by providing a better understanding of neurochemical mechanisms involved in brain function and for possible development of new neuropharmacological and therapeutic tools.

No abstract

No abstract

PPV with SOI was associated with retinal cell death and disorganization in rabbit eyes. Intramuscular ketamine administration provided protection against these effects.

The activities of daily living are routine self-maintenance tasks. Children with cerebral palsy can have difficulties, which can vary according to their level of motor impairment, in the performance of functional activities such as feeding and dressing themselves. The use of digital memory gaming can be a play activity and a technological resource that stimulates cognitive skills and contributes to the development of persons with disabilities. The objective of this article is to analyze the usability and effectiveness of a digital memory game for activities of daily living with children with cerebral palsy. Two children with cerebral palsy, one aged 5 and the other aged 7, participated in the investigation. The results obtained in the usability analysis are satisfactory because there were no major problems with the interface and the time available for the game and the rules presented were observed. The results also reveal the effectiveness of digital memory gaming for the recognition of objects and the activities of daily life. The importance of digital memory gaming for children with cerebral palsy is discussed.

No abstract

No abstract