BRASILIA( REUTERS)-A Brazilian hospital chain tested unproven drugs on elderly Covid-19 patients without their knowledge as part of an effort to validate President Jair Bolsonaro's preferred" miracle cure", a lawyer for whistleblowing doctors told senators on Tuesday( Sept 28).At least nine people died of Covid-19 during the trials at the Prevent Senior hospital chain from March to April 2020, but their charts were altered to hide the cause of death, lawyer Bruna Morato told a Senate inquiry. Pr