Safety and efficacy of erythrocyte encapsulated thymidine phosphorylase in mitochondrial neurogastrointestinal encephalomyopathy by Levene, M, Bain, MD, Moran, NF, Nirmalananthan, N, Poulton, J, Scarpelli, M, Filosto, M, Mandel, H, Mackinnon, AD, Fairbanks, L, Pacitti, D, Bax, BE