[1] Radboud Univ Nijmegen Med Ctr, Dept Internal Med, Div Gen Internal Med, NL-6525 GA Nijmegen, Netherlands
[2] Univ Florence, Dept Clin Pathophysiol, I-50121 Florence, Italy
[3] NICHHD, Reprod Biol & Med Branch, NIH, Bethesda, MD 20892 USA
[4] Natl Inst Neurol Disorders & Stroke, Clin Neurocardiol Sect, NIH, Bethesda, MD USA