Clinical review 5: Recombinant DNA strategies for determining the molecular basis of endocrine disorders

A case of idiopathic thyrotropin (TSH) deficiency

The first case of idiopathic thyrotropin (TSH) deficiency in an old woman with thyroid functioning adenoma was reported. She got subtotal thyroidectomy before about four years of her admission to our hospital because of fatigability, puffy face and leg edema. At time, she had low TSH and free T4 levels despite replacement therapy with desiccated thyroid. No response of only serum TSH after administration of combined stimulant containing TRH and repeated TRH suggested the failure of TSH secretion. CT MRI did not show any abnormality. These results indicated that her hypothyroidism was due to acquired idiopathic TSH deficiency.

Introduction to molecular endocrine pathology

The applications of molecular techniques to endocrine pathology have been rapidly expanding in the past few years. This article reviews some of the basic concepts and techniques in molecular biology and summarizes recent applications of these techniques in the study of endocrine diseases. The applications of clonal analysis, hybridization techniques, single strand conformation polymorphism analysis, and the polymerase chain reaction technique in the study of neoplasms including specific mutations of oncogenes and suppressor genes in various endocrine tissues are discussed. The rapidly developing field of homeobox genes and their role in development including studies of normal pituitary development and pituitary tumor expression of the Pit-1 transcription factor, a member of the POU family of homeobox genes, are also summarized.Endocr Pathol 4:64-72, 1993.

Advances in molecular biology. Potential impact on diagnosis and treatment of disorders of the thyroid

Advances in molecular biology research continue to have a major impact on clinical medicine. These advances have provided a means to produce proteins previously available in limited supply and allow for the production of novel proteins that are improved agonists or else antagonists with greater specificity for therapeutic targets. Newer drug delivery systems should facilitate delivery of these proteins. By combining the capabilities to produce drug targets in acceptable quantities with improved methods for determining the three-dimensional structures of these targets, novel organic therapeutic molecules that act on these targets will be designed. Gene transfer therapy using genes that express important proteins or that encode "antisense" RNAs that inhibit the translation of specific mRNAs will soon become a reality. The use of RFLPs and PCR methodologies promises increased means to diagnose specific genetic diseases and infections. Most importantly, molecular biology is helping to understand the mechanisms of disease such that novel diagnostic and therapeutic approaches can be described. These advances are providing an understanding of the mechanisms involved in cancers of the thyroid gland. They have already led to an enhanced understanding of (1) the growth factors that control proliferation of the thyroid gland, (2) the potential steps in thyroid nodule and neoplasia development, (3) particular mutations that may occur as thyroid cancers develop, (4) oncogenes that are expressed in thyroid cancers, and (5) the genetic defects that are responsible for thyroid gland malignancies in the multiple endocrine neoplasia (MEN) syndromes. With the latter, the RFLP technology has already provided an enhanced means to diagnose the disorder. With further progress, enhanced means for diagnosis and treatment should emerge. Molecular biology techniques are contributing to an increased understanding of the mechanisms of development of autoimmune thyroid disease as with Graves' disease and Hashimoto's thyroiditis. The potential role of infections, histocompatibility antigens, thyroid gland and extraglandular antigens, immune modulators, subpopulations of T-cells such as suppressor and helper cells, other cells involved in immune responses, and a combination of influences of several different functions on the thyroid gland are being defined. This knowledge should soon suggest improved means for diagnosis and treatment. Understanding of the function of the thyroid hormone receptors should have clinical importance. This knowledge suggests a means to develop thyroid hormone antagonists that may be used to more rapidly ameliorate the effects of hyperthyroidism and could be useful in nonthyroidal disorders such as cardiac arrhythmias.(ABSTRACT TRUNCATED AT 400 WORDS)