Under heavy security that appeared intended to keep the press at bay, Sen. Edward Kennedy (D-Mass.), who is undergoing treatment for a brain tumor, arrived in the Senate today for the Medicare vote. The Massachusetts Senator looked robust and appeared to be faring well a little over a month after surgery. He is still undergoing radiation and chemotherapy. When asked how he was feeling, Kennedy replied, good. But the Senator would not say how long he planned to stay in Washington. Kennedy’s colleagues gave him a standing ovation as he entered the chamber to cast his votes to claps and cheers. It is the first time he has appeared on the floor since his diagnosis on May 20.