ABSTRACT
Small nuclear RNAs (snRNAs) are important factors in the functioning of eukaryotic cells that form several small complexes with proteins; these ribonucleoprotein particles (U snRNPs) have an essential role in the pre-mRNA processing, particularly in splicing, catalyzed by spliceosomes, large RNA-protein complexes composed of various snRNPs. Even though they are well defined in mammals, snRNPs are still not totally characterized in certain trypanosomatids as Trypanosoma cruzi. For this reason we subjected snRNAs (U2, U4, U5, and U6) from T. cruzi epimastigotes to molecular characterization by polymerase chain reaction (PCR) and reverse transcription-PCR. These amplified sequences were cloned, sequenced, and compared with those other of trypanosomatids. Among these snRNAs, U5 was less conserved and U6 the most conserved. Their respective secondary structures were predicted and compared with known T. brucei structures. In addition, the copy number of each snRNA in the T. cruzi genome was characterized by Southern blotting.
Subject(s)
Animals , Genome, Protozoan/genetics , RNA, Small Nuclear/genetics , Trypanosoma cruzi/genetics , Blotting, Southern , Cloning, Molecular , Polymerase Chain Reaction/methods , RNA SplicingABSTRACT
Um dos modelos comportamentais mais utilizados na avaliacao de drogas antipsicoticas é o da pre-exposicao ao estímulo a ser condicionado, ou inibiçäo latente(LI). Na LI, a exposiçäo prévia a um estímulo sem consequencia retarda a aprendizagem, quando esse mesmo estímulo, numa fase posterior, é pareado com um reforçador. Neste artigo é feita, preliminarmente, uma revisäo da utilizaçäo da LI como modelo animal para avaliaçäo de drogas antipsicóticas, e de seu fundamento neuroquímico. A seguir, discutem-se os processos comportamentais implicados na pré-exposiçäo, e que explicariam o desempenho na fase de condicionamento. Duas teorias principais säo examinadas, à luz dos paradigmas respondentte e operante do comportamento: 1) a de Mackintosh, que considera que a aprendizagem deirrelevancia do estímulo ocorre quando esse näo sinaliza nenhuma mudança em um reforçador específico, e 2) a de Lubow, que defende a existencia de uma hipotética resposta de atençäo que decresceria aao longo de repetidas exposiçöes ao estímulo, o que diminuiria sua futura associabilidade quando na funçäo de estímulo condicional
Subject(s)
Animals , Schizophrenia , Inhibition, PsychologicalABSTRACT
The selective serotonin reuptake inhibitor fluoxetine (FLX) is widely prescribed for depression and anxiety-related disorders. On the other hand, enhanced serotonergic transmission is known to be classically related to anxiety. In this study, the effects of acute (5.0 mg/kg) and chronic (5.0 mg/kg, 22 days) FLX were investigated in both food-deprived and non-deprived rats tested in the elevated plus-maze. Significant main effects of the three factors (drug, food condition and administration regimen) were observed, but no interaction between them. The administration of either acute or chronic FLX resulted in an anxiogenic effect, as detected by a significant reduction in the percentage of time spent in the open arms and in the percentage of open arm entries. Food deprivation yielded an anxiolytic-like profile, probably related to changes in locomotor activity. The administration regimen resulted in an anxiolytic profile in chronically treated rats, as would be expected after 22 days of regular handling. The anxiogenic action of acute FLX is consistent with both its neurochemical and clinical profile. The discrepancy between the anxiogenic profile of chronic FLX and its therapeutic uses is discussed in terms of possible differences between the type of anxiety that is measured in the plus-maze and the types of human anxiety that are alleviated by fluoxetine
Subject(s)
Animals , Male , Fluoxetine/pharmacology , Maze Learning/drug effects , Selective Serotonin Reuptake Inhibitors/pharmacology , Analysis of Variance , Anxiety Disorders/drug therapy , Fluoxetine/therapeutic use , Food Deprivation , Handling, Psychological , Rats, WistarABSTRACT
As indicaçöes no tratamento de lesöes coronárias complexas foram ampliadas com o avanço técnico e tecnológico da Cardiologia Intervencionista. Dentre as técnicas desenvolvidas para superar as limitaçöes no tratamento de lesöes coronárias, a aterectomia coronária rotacional é uma delas. Cabe à enfermagem a atualizaçào constante e, por meio da sistematizaçäo da assistência, prestar os cuidados no pé, no trans e no pós-procedimento, contribuindo assim para osucesso da nova técnica e para a boa evoluçädo paciente durante a fase hospitalar.