In the past five years, so much additional progress has been made in ourunderstanding of both the basic and c1inical aspects of a wide variety of thyroid disorders that a second edition of Diseases of the Thyroid was considered a necessary addition to the Contem­ porary Endocrinology series. Fresh perspectives also seemed warranted, so we recruited new authors for many of the chapters and believe that this edition will provide the reader with further insights into the pathophysiology and c1inical presentation and treatment of thyroid disease. It inc1udes topics ranging from neonatal thyroid screening, thyroid dysfunction during infancy and childhood, peripartum thyroid disorders, thyroid disease in the elderly, and the c1inical relevance of the sodiurnliodide symporter (NIS) to the pathogenesis and treatment of nodular goiter, thyroid cancer, thyrotoxicosis, and hypothyroidism. The worldwide problem of iodine deficiency and its eradication is also discussed, along with environmental goitrogens and iodine-induced thyroid disease. I am indebted to all the contributors for their cooperation and expertise in providing their chapters in an extremely timely fashion, to Mr. Thomas Moore and Mr. Craig Adams from Humana Press for their expert assistance, and to Ms. Christine Archung for providing superb administrative assistance. Lewis E. Braverman, MD v CONTENTS Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Molecular Mechanisms of Nuclear Thyroid Hormone Action William W. Chin and Paul M. Yen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 Nongenomic Actions of Thyroid Hormone Paul 1. Davis and F aith B. Davis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3 Thyroid Testing: A Clinical Approach Laurie A. Kane and Hossein Gharib . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .