New research suggests that the drug Tysabri may regenerate and stabilize damage done to the myelin sheath in people with multiple sclerosis (MS). In a new study, scientists gave MS patients either Tysabri, interferon beta-1a, or no drugs at all. They then used advanced MRI scans to measure lesions and normal brain tissue in the patients. The investigators found that after 12 months of follow-up, the 62 patients who took Tysabri showed remyelination when compared to patients in the other two...