The current treatment for patients with hypothyroidism is levothyroxine (L-T4) along with normalization of serum thyroid-stimulating hormone (TSH). However, normalization of serum TSH with L-T4 monotherapy results in relatively low serum 3,5,3'-triiodothyronine (T3) and high serum thyroxine/T3 (T4/T3) ratio. In the hypothalamus-pituitary dyad as well as the rest of the brain, the majority of T3...

A cross-sectional study of thyrotropin (TSH), thyroxine (T4) and triiodothyronine (T3) in human serum was performed aiming to define their normal values. In total, 201 assays were performed on 70 normal individuals, 26 men and 44 women, with ages ranging from 2 to 84 years. Serum TSH was measured with a highly sensitive immunoradiometric assay (IRMA) kit and T4 & T3 were determined with commerc...

OBJECTIVE Pubertal gynaecomastia is a frequent phenomenon occurring in 20-40% of otherwise healthy adolescent boys. Little is known about the aetiology of pubertal gynaecomastia. Markedly elevated thyroid hormone levels in adults with hyperthyroidism are associated with gynaecomastia. DESIGN A cross-sectional examination of 444 healthy boys with and without pubertal gynaecomastia. METHODS W...

BACKGROUND Previous studies have suggested an association between subclinical hypothyroidism and coronary artery disease that could be related to changes in serum lipids or endothelial dysfunction. METHODS Thirty-two female subclinical hypothyroidism patients were randomly assigned to 12 months of L-thyroxine replacement or no treatment. Endothelial function was measured by the flow-mediated ...

The interaction was examined in vitro of retinoic acid and thyroid hormone with rabbit reticulocyte Ca2(+)-ATPase. L-Thyroxine (T4) (0.1 nM) stimulated female-source Ca2(+)-ATPase activity (+21%; P less than 0.03) and inhibited male-source enzyme (-20%; P less than 0.05). Addition of retinoic acid (10 nM-1 microM) did not influence T4-inhibitable male-source Ca2(+)-ATPase, but caused a 52% loss...

The thyroid gland is an endocrine organ that secretes the hormones triiodothyronine (T3) and thyroxine (T4), which are, in turn, under the influence of the TSH and the TRH. Though hyperand hypothyroidism remain the common clinically manifesting condition of the thyroid, in some cases, the patient remains symptomless with either excess or decrease in thyroxine levels, along with normal TSH level...

The thyroid gland is an endocrine organ that secretes the hormones triiodothyronine (T3) and thyroxine (T4), which are, in turn, under the influence of the TSH and the TRH. Though hyperand hypothyroidism remain the common clinically manifesting condition of the thyroid, in some cases, the patient remains symptomless with either excess or decrease in thyroxine levels, along with normal TSH level...

The effect of thyroid hormone on the serum level of somatomedin A was studied using a radioreceptor assay for somatomedin A. In 13 patients with hyperthyroidism, the mean level of somatomedin A was 0.06 +/- 0.05 U/ml, which was within the normal range. Low levels were found in 19 patients with primary hypothyroidism with a mean of 0.39 +/- 0.04 U/ml. After treating these patients with thyroxine...

BACKGROUND AND AIMS Certain endocrinological disturbances are assumed to exacerbate psoriasis. In this study we compared the serum thyroid hormone levels of a group of psoriasis patients with that of a control group. METHODS The total T3 (TT3), free T3 (FT3), total T4 (TT4), free T4 (FT4) and TSH levels obtained from the sera of 103 psoriatics (37 males and 66 females) and 96 controls (40 mal...

UNLABELLED The standard treatment of hypothyroidism (central and primary) consists of thyroxine (T4) administration alone. However, the normal thyroid gland produces a small proportion of triiodothyronine (T3) directly into the circulation. AIM We aimed to study the free T3 to free T4 ratio in treated central hypothyroidism compared with euthyroidism and treated primary hypothyroidism. METH...