thiourea and Thyroid-Diseases

Topics: Amino Acids; Animals; Autoradiography; Biological Evolution; Carbon Radioisotopes; Catecholamines; Dopa Decarboxylase; Fetus; Humans; Iodine; Iodine Radioisotopes; Iodoproteins; Melanins; Metamorphosis, Biological; Monoiodotyrosine; Neurotransmitter Agents; Sympathetic Nervous System; Thiourea; Thyroid Diseases; Thyroid Gland; Thyroxine; Tyrosine

Time course changes in serum TSH and quantitative data for thyroid proliferative lesions in male F344 rats administered N-bis(2-hydroxypropyl)nitrosamine (DHPN: 2000 mg/kg body weight, single s.c. injection) followed by 0.1% thiourea (TU), were assessed at weeks 1, 2, 4, 8, 12 and 16 of treatment. The serum T4 level in the TU group was markedly decreased at week 1 and remained significantly lowered throughout the experiment. Serum TSH levels, in contrast, were elevated up to a peak at around week 4 with a return to the normal range at week 12. Thyroid weights in the TU group were increased significantly in a treatment period-dependent manner. Histopathologically, marked hypertrophy of thyroid follicular cells occurred at the early stage of TU treatment. Proliferative lesions, such as hyperplasia and adenomas, occurred from weeks 2 and 4, respectively, and increased with the later treatment period. The cell proliferative activity of follicular cells, assessed by BrdU incorporation, was high until week 2, but then returned to normal. The initially appearing hyperplasias and adenomas were characterized by marked proliferation but this also greatly decreased at later stages when TSH was no longer elevated. The results of our study thus suggest that a high serum TSH level plays an important role in the early phase of thyroid tumorigenesis and 8 weeks treatment with test substances is sufficient for detection of thyroid tumor promoter potential in two-stage thyroid carcinogenesis models.

Topics: Adenoma; Animals; Body Weight; Carcinogens; Cell Division; Drug Administration Schedule; Hyperplasia; Male; Nitrosamines; Organ Size; Pituitary Gland; Rats; Rats, Inbred F344; Thiourea; Thyroid Diseases; Thyroid Gland; Thyrotropin; Time Factors

To accurately evaluate thyroid disorders in pregnancy, the physician must understand the physiologic changes that occur both in thyroid gland size and in thyroid function tests. The effect of thyrotoxicosis on pregnancy outcome largely depends on whether metabolic control is achieved. Women who become euthyroid on treatment usually can expect satisfactory outcomes. Propylthiouracil is considered to be the drug of choice for treating thyrotoxicosis during pregnancy. Because of the significant risk of hypothyroidism and obvious goiter in the infant, the use of iodide should be reserved for severe disease, such as thyroid storm or heart failure. Thyrotoxic infants may need antithyroid treatment until TSAbs are metabolized. Since overt hypothyroidism is often associated with infertility, it is uncommon in pregnancy. Hypothyroid women who do become pregnant, however, have an increased risk of low-birth-weight or stillborn infants. These women may require a greater dosage of thyroid hormone during pregnancy. The effects of subclinical hypothyroidism are not well defined. Accordingly, the need for treatment hinges on the woman's clinical history. Infants of hypothyroid mothers usually show no evidence of thyroid dysfunction, but those who are hypothyroid should receive prompt thyroid replacement therapy. To minimize the sequelae of congenital hypothyroidism, mass screening of infants and prompt treatment of those affected is recommended. During pregnancy, thyroid nodules should be evaluated by ultrasound and fine-needle aspiration or tissue biopsy. Radioiodine scanning should be avoided during pregnancy. If thyroid cancer is diagnosed, pregnancy should not delay treatment. Because postpartum thyroid dysfunction is fairly common yet difficult to detect, physicians and patients should be aware of the symptoms and risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Female; Humans; Hyperthyroidism; Hypothyroidism; Infant, Newborn; Postpartum Period; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Thiourea; Thyroid Crisis; Thyroid Diseases; Thyrotoxicosis

Topics: Air Pollutants, Occupational; Chemical Industry; Humans; Occupational Diseases; Thiourea; Thyroid Diseases

Topics: Adult; Ageusia; Female; Humans; Middle Aged; Olfaction Disorders; Taste Disorders; Thiourea; Thyroid Diseases; Zinc

A 0.2% solution of 2-thiourea administered during the third or the second and third weeks of pregnancy increased the weight of the thyroid of 20-day old fetuses and newborn rats, and decreased the protein bound iodine content in their thyroid and serum. Similar changes were observed in those weanling rats whose mother had been given a 0.2% solution of thiourea during the period of lactation. Both the intrauterine changes and those occurring during lactation proved reversible. The findings point to the possibility of congenital or infantile thyroid injury caused by thiourea derivatives taken up from the environment.

Topics: Animals; Animals, Newborn; Blood Proteins; Female; Iodine; Maternal-Fetal Exchange; Organ Size; Pregnancy; Protein Binding; Rats; Thiourea; Thyroid Diseases; Thyroid Gland

Topics: Animals; Connective Tissue; Cysts; Epithelial Cells; Epithelium; Fishes; Gonads; Hyperemia; Hyperplasia; Hypertrophy; Injections, Intraperitoneal; Iodine Isotopes; Pituitary Gland; Temperature; Thiourea; Thyroid Diseases; Thyroid Gland

Topics: Humans; Industry; Occupational Diseases; Thiourea; Thyroid Diseases

Topics: Antineoplastic Agents, Hormonal; Thiouracil; Thiourea; Thyroid Diseases; Thyroid Gland

Topics: Heart Failure; Hyperthyroidism; Methylthiouracil; Thiourea; Thyroid Diseases

Topics: Graves Disease; Humans; Iodides; Iodine; Methylthiouracil; Thiourea; Thyroid Diseases

Topics: Graves Disease; Propylthiouracil; Thiourea; Thyroid Diseases

Topics: Animals; Hyperplasia; Rats; Thiouracil; Thiourea; Thyroid Diseases