1. Thyroid Section, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
2. Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest H-1083, Hungary
3. Département de Biologie structurale, IMPMC, CNRS UMR7590, Universities Paris 6 and Paris 7, Paris 75252 Cedex 05, France