U.S. expert visits London hospital to examine baby Charlie Gard

By Michael HoldenLONDON (Reuters) - A U.S doctor offering experimental treatment to a critically ill British baby visited the London hospital where he is being treated on Monday as part of a last-ditch attempt to persuade a judge to keep the boy's life support switched on.The parents of Charlie Gard, who has a rare genetic condition causing progressive muscle weakness and brain damage, have been fighting a legal battle to send him to the United States for the neurologist's experimental therapy.T