Aspectos Neurodesenvolvimentais e Relacionais do bebê com Síndrome de Down

Dentre as inúmeras patologias que afetam a infância, a Síndrome de Down (SD) destaca-se por provocar alterações globais no processo de desenvolvimento. Nos últimos anos, principalmente devido à sua alta incidência, diversas pesquisas têm sido empreendidas com o intuito de melhor compreender esta síndrome, o que tem trazido importantes contribuições ao conhecimento na área. Entretanto, verificam-se, ainda, lacunas no tocante à compreensão das mudanças e transformações que caracterizam o desenvolvimento dessas crianças, especialmente no que concerne aos estágios mais precoces do seu desenvolvimento. Com o objetivo de contribuir com este campo de pesquisa, o presente artigo objetivou apresentar resumidamente os principais aspectos acerca do neurodesenvolvimento e desenvolvimento relacional dos bebês com SD. Espera-se, com isto, contribuir com a literatura na área ao destacar ambos os aspectos no início da vida do bebê e facilitar, assim, o resgate por estudantes e pesquisadores dos estudos sobre a SD.

Senescence-associated β-galactosidase activity in the in vitro ovarian stromal fibroblasts

Introduction: A growing biological research field is the cellular senescence, a mechanism that has been associated, under certain circumstances, with malignant transformation. Given the high incidence of ovarian cancer and its main origin from the ovarian surface epithelium, as well as the possibility that an epithelial-mesenchymal transition occurs, we evaluated both the in vitro growth of stromal fibroblasts from the ovarian cortex and their β-galactosidase activity at pH 6, enzyme whose expression is considered as a marker of replicative senescence. Methods: 48 samples of ovarian cortical fibroblasts from donors without a history of cancer were serially cultured until the end of their replicative life. β-galactosidase activity at pH 6 was quantified in each passage by the chemiluminiscent method. As control, we used ovarian epithelial cell cultures from the same donors. The enzyme activity was also evaluated in fibroblasts previously induced to senescence by exposure to hydrogen peroxide. Results: The analysis of the enzyme activity and the replicative capacity taken together showed that the fibroblast cultures reached the senescent state at passages 4-5, as what happened with the control epithelial cells. Fibroblasts induced to senescence showed high variability in the values of enzymatic activity. Conclusions: The similarity between both types of cells in reaching the senescent state deserves to be taken into account in relation to the epithelialmesenchymal transition that has been proposed to explain their behavior in the genesis of cancer arising from ovarian surface epithelium. Low β-galactosidase activity values at pH 6 would suggest possible inactivation of the response pathways to oxidative stress.