Questões de Concursos 2015

Clues to How an Electric Treatment for Parkinson’s Work

In 1998, Dr. Philip A. Starr started putting electrodes in people’s brains. A neurosurgeon at the University of California, San Francisco, Dr. Starr was treating people with Parkinson’s disease, which slowly destroys essential bits of brain tissue, robbing people of control of their bodies. At first, drugs had given his patients some relief, but now they needed more help. After the surgery, Dr. Starr closed up his patients’ skulls and switched on the electrodes, releasing a steady buzz of electric pulses in their brains. For many patients, the effect was immediate. “We have people who, when they’re not taking their meds, can be frozen,” said Dr. Starr. “When we turn on the stimulator, they start walking.” First developed in the early 1990s, deep brain stimulation, or D.B.S., was approved by the Food and Drug Administration for treating Parkinson’s disease in 2002. Since its invention, about 100,000 people have received implants. While D.B.S. doesn’t halt Parkinson’s, it can turn back the clock a few years for many patients. Yet despite its clear effectiveness, scientists like Dr. Starr have struggled to understand what D.B.S. actually does to the brain. “We do D.B.S. because it works,” said Dr. Starr, “but we don’t really know how.” In a recent experiment, Dr. Starr and his colleagues believe they found a clue. D.B.S. may counter Parkinson’s disease by liberating the brain from a devastating electrical lock-step.

http://www.nytimes.com/2015/04/16/science/ (adapted)

Meu bem, meu mal

     Até um tempo atrás o cafezinho era tido como inimigo da boa saúde. O mesmo acontecia com a carne vermelha, o ovo, o chocolate – todos recentemente absolvidos, depois que pesquisas modernas descobriram novos (e saudáveis) componentes nesses alimentos. Ou desde que estudos mais abrangentes mostraram que ficar sem eles é pior do que consumi-los. Afinal, por que as conclusões da ciência mudam tanto?
     Para começar, essas diferenças nos estudos não espantam os médicos – que, aliás, até esperam que elas ocorram. A medicina, assim como a nutrição, não é ciência exata. Nem sempre o que é verdade hoje será verdadeiro no futuro.
     Um dos motivos para as mudanças é o avanço da tecnologia. Com o uso de computadores e da internet, é claro que resultados conseguidos nos anos 40, em estudos de colesterol, por exemplo, são bem menos exatos do que os atuais.

(Revista Dossiê Superinteressante. jan. 2015. Adaptado)