4] Laboratory of Clinical Chemistry and Radioimmunology
University Hospital of the Free University Brussels Brussels, Belgium
Johan Schiettecatte,  Anne Van Opdenbosch,  Ellen Anckaert,  Jean De Schepper,  Kris Poppe,  Brigitte Velkeniers,  and Johan Smitz  ( Laboratory of Radioimmunology
and  Department of Endocrinology, University Hospital, Vrije Universiteit, Brussels, Belgium; * address correspondence to this author at: Laarbeeklaan 101, B-1090 Brussels, Belgium; fax 32-2-477-50-60, e-mail Johan.
We are highly grateful to the technical staff of the radioimmunology
unit of the Laboratoire Marcel Merieux (Lyon, France); to Christine Ferret, Patricia Herviaux, and Philippe Bonnet (Physiology Laboratory, Hopital Necker-Enfants Malades, Paris, France); and to Christine Dufour (Laboratoire de Biochimie, Hopital de Gonnesse, Gonnesse, France) for their excellent technical work.