ABSTRACT The sensitive and tightly regulated feedback control system, thyroid gland autoregulation, and the large intrathyroidal and extrathyroidal storage pools of thyroid hormone serve to provide a constant supply of thyroid hormone to peripheral tissues in the face of perturbations imposed by the external environment, chemicals and drugs, and a variety of diseases processes. The […]
ABSTRACT Multinodular goiter (MNG) is the most common of all the disorders of the thyroid gland. MNG is the result of the genetic heterogeneity of follicular cells and apparent acquisition of new cellular qualities that become inheritable. Nodular goiter is most often detected simply as a mass in the neck, but sometimes an enlarging gland […]
ABSTRACT Thyroid disease in pregnancy is a common clinical problem. During the past 2 years significant clinical and scientific advances have occurred in the field. This chapter reviews the physiology of thyroid and pregnancy focusing on iodine requirements and advances in placental function. There follows discussion on thyroid function tests in pregnancy and their interpretation […]
ABSTRACT Thyroid cancer accounts for only 0.4% of all cancer deaths, with an incidence of 11 cases and about 0.5-0.6 deaths per 100,000 population in the United States each year,according to the November 2011 SEER report (http://seer.cancer.gov/statfacts/html/thyro.html). Its clinical importance, by contrast, is out of all proportion to its incidence, because cancers of the thyroid […]
ABSTRACT The biological activity of thyroid hormone (TH) is regulated at the target tissue level by two important processes, i.e. deiodination and plasma membrane transport. The first process involves the expression of the deiodinase D2, which converts the prohormone T4 to bioactive T3, and/or of the deiodinase D3 which converts both T4 and T3 to […]
ABSTRACT This discussion stresses the normal occurrence of immune self-reactivity, the genetic and environmental forces that may amplify such responses, the role of the antigen-driven immune attack, secondary disease-enhancing factors, and the important contributory role of antigen-independent immune reactivity. Research on thyroid autoimmunity has benefited greatly by knowledge of the specific target antigens and easy […]
ABSTRACT Incidence rates of thyroid cancer have increased substantially worldwide in the past several decades. Thus, diseases of the thyroid gland and their treatment remain one of the most interesting and dynamic areas of study in medicine. This chapter presents a clear and concise description of current thought and practice concerning the surgical treatment of […]
ABSTRACT The main function of the thyroid gland is to make hormones, T4 and T3, which are essential for the regulation of metabolic processes throughout the body. As at any factory, effective production depends on three key components – adequate raw material, efficient machinery, and appropriate controls. Iodine is the critical raw material, because 65% […]
ABSTRACT This chapter presents an analysis and a summarized synthesis of our present knowledge of the biology of the thyroid gland, phylogeny ,ontogeny ,anatomy ,structure ,general metabolism ,regulatory factors and hormones , signalling cascades and their regulations , ( eg TSH ), functions including iodine metabolism and thyroid hormones synthesis , control of gene expression ,differentiation […]
ABSTRACT Graves’ disease includes thyrotoxicosis, goiter, exophthalmos, and pretibial myxedema when fully expressed, but can occur with one or more of these features. Graves’ disease is a disease of “autoimmunity”, but the final cause of autoimmunity remains unclear. A strong hereditary tendency is present. Inheritance of HLA antigens DR3, DQ 2, and DQA1*0501 predispose to […]
ABSTRACT NTIS refers to a syndrome found in seriously ill or starving patients with low fT3, usually elevated RT3, normal or low TSH, and if prolonged, low fT4. It is found in a high proportion of patients in the ICU setting, and correlates with a poor prognosis if TT4 is <4ug/dl. The patho-physiology includes […]
9.1 HISTORICAL The full-blown expression of hypothyroidism is known as myxedema. Adult myxedema escaped serious attention until Gull described it in 1874 1 . That it was a state resembling the familiar endemic cretinism, but coming on in adult life, was what chiefly impressed Gull. Ord 2 invented the term myxedema in 1873. The disorder […]
Incidence and Distribution The annual incidence of thyroid cancer varies considerably in different registries, ranging from 1.2-2.6 per 100,000 individuals in men and from 2.0-3.8 per 100,000 in women (106,107). It is particularly elevated in Iceland and Hawaii, being nearly two times higher than in North European countries, Canada and the USA. In Hawaii, the […]
INTRODUCTION Thyrotoxicosis is defined as the clinical syndrome of hypermetabolism resulting from increased free thyroxine (T4) and/or free triiodothyronine (T3) serum levels (1). The term thyrotoxicosis is not synonymous with hyperthyroidism, the elevation in thyroid hormone levels caused by an increase in their biosynthesis and secretion by the thyroid gland (Table 1) (2). For example, […]
Archived This chapter has been superceded by newer chapters (See Homepage). However this Chapter, written originally by Dr Samuel Refetoff and updated by Drs Franklyn and Shephard, remains a treasure trove of information on many now-obscure thyroid tests, and references. For that reason we maintain it as a part of our Archive for use of […]