Thyroid : official journal of the American Thyroid Association
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Active and passive cigarette smoking are a risk factor among women of reproductive age-leading to reproductive health morbidity, including fetal and infant death and developmental problems with the newborn. However, the underlying physiological mechanisms for these ill-effects are not fully understood. Smoke exposure may affect various metabolic and biological processes, including hormone biosynthesis and secretion, interfere with thyroid hormone release, binding, transport, storage, and clearance, associated with adverse effects on the thyroid resulting in changes in circulating hormone concentrations. We measured and compared serum thyroid hormone and thyroid stimulating hormone (TSH) concentrations in active, passive, and nonsmokers and determined their association with cigarette tobacco smoke exposure. We use a comprehensive approach to assess the interrelationships between active and passive tobacco smoke exposure and thyroid hormone levels by employing innovative hormone analysis techniques. ⋯ This study is unique in examining the association of serum cotinine and thyroid hormone concentrations using liquid chromatography tandem mass spectrometry in women smokers, passive smokers, and nonsmokers. Active and passive exposure to cigarette tobacco smoke is associated with a mild inhibitory effect on the thyroid reflected in higher serum T4 and T3 in nonsmokers compared to smokers in this cohort of women.
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Maternal hypothyroxinemia, due to gestational iodine deficiency, causes neurological dysfunctions in the progeny. Our aim was to determine the effects of delayed iodine supplementation (200 microg KI per day) to mildly hypothyroxinemic pregnant women at the beginning of gestation (i.e., having circulating free thyroxine [FT(4)] within the 0th-10th percentile interval and normal thyrotropin [TSH]) on the neurobehavioral development of their children. ⋯ A delay of 6-10 weeks in iodine supplementation of hypothyroxinemic mothers at the beginning of gestation increases the risk of neurodevelopmental delay in the progeny. Public health programs should address the growing problem of iodine deficiency among women of gestational age in developing and industrialized nations.
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Case Reports
Two patients with highly aggressive macrofollicular variant of papillary thyroid carcinoma.
The macrofollicular variant of papillary thyroid carcinoma (MFV-PTC) is an unusual type of thyroid carcinoma with histological features that can be confused with nodular goiter or follicular adenoma. It generally has a good prognosis and low incidence of metastases. We report two patients with highly aggressive MFV-PTC including bone metastases, one of whom died of their disease. ⋯ To our knowledge these are the first cases of MFV-PTC reported with bone metastasis. Although MFV-PTC usually has a good prognosis these cases highlight the importance of careful histopathological examination for MFV-PTC in thyroidectomy specimens that may appear to be seemingly benign nodular thyroid disease.