ABSTRACT
BACKGROUND: X-Fragile Syndrome. AIM: To compile information about the language, cognitive and behavior alterations in the X-Fragile Syndrome, using the results of previously published studies and to present the standardized instruments used as testing materials. CONCLUSION: studies used formal and informal testing to assess language. The results present variability regarding the linguistic deficits, which are influenced by the level of the cognitive deficit and behavior alterations. Alterations of the oral praxes and of speech articulation are also expected.
Tema: síndrome do X-Frágil. Objetivo: compilar informações sobre as alterações de linguagem, cognição e comportamento na Síndrome do X-Frágil por meio do resultado de estudobibliográfico e apresentar os instrumentos padronizados usados nas avaliações. Conclusão: os estudos utilizaram procedimentos formais e informais para a avaliação da linguagem. Os resultados apresentaram variabilidade quanto às alterações lingüísticas, sofrendo influênciaquanto ao grau de retardo mental, e distúrbios comportamentais. Alterações práxicas orais e fonoarticulatórias também são previstas.
Subject(s)
Humans , Fragile X Syndrome/psychology , Language Tests , Cognition Disorders/psychology , Language Disorders/psychology , Phonetics , Language , Fragile X Syndrome/physiopathology , Cognition Disorders/diagnosis , Language Disorders/diagnosisABSTRACT
Adenosine inhibition of hormone-sensitive adenylate cyclase activity was investigated using isolated myocardial membranes prepared from rat hearts. When cyclase activity was determined in membranes, using [alpha-32P]ATP as substrate, 10(-5) M adenosine inhibited isoproterenol-stimulated adenylate cyclase activity by 25% but did not inhibit basal activity or fluoride (5 mM) activation of the enzyme. The adenosine reduction of isoproterenol-sensitive cyclase activity was dependent on GTP but was not prevented by 10(-3) M theophylline. Adenosine neither appeared to compete with ATP for the substrate converting site of the enzyme nor reduced 5'-guanylyl imidodiphosphate activation of the enzyme. Inasmuch as lower concentrations of adenosine had no influence on enzyme activity, endogenous adenosine may be present in the adenylate cyclase assay. To obviate the effects of endogenous adenosine, the adenylate cyclase assay was then modified to a 2'-deoxy system with [alpha-32P]dATP used as the substrate in the presence of adenosine deaminase. With this assay system, the 15% inhibition of isoproterenol-stimulated adenylate cyclase activity produced by the adenosine receptor agonists, 10(-8) M 2-chloroadenosine or phenylisopropyladenosine, was prevented by 10(-4) M 8-phenyltheophylline or isobutylmethylxanthine (IBMX), respectively. While under these assay conditions, 10(-7) M 2',5'-dideoxyadenosine, a P-site analogue, did not influence the hormone-sensitive cyclase activity. The 35% reduction of the hormone-sensitive enzyme produced by this analogue at 10(-5) M was not prevented by IBMX. These results suggest that nanomolar concentrations of adenosine analogues interact with a methylxanthine-sensitive adenosine receptor that mediates the attention of membrane hormone-sensitive adenylate cyclase activity.
