Cortical excitability in patients with resistance to thyroid hormone compared to patients with hypothyroidism and euthyroid controls: a transcranial magnetic stimulation study.

Resistance to thyroid hormone (RTH) describes a rare syndrome in which serum levels of thyroid hormones are elevated but serum levels of thyroid stimulating hormone (TSH) are unsuppressed. The importance of thyroid hormones for the normal function of the adult brain is corroborated by the frequent association of thyroid dysfunctions with neurological and psychiatric symptoms. In this study we investigated whether adult thyroid hormone resistance affects cortical excitability and modulates inhibitory and excitatory intracortical circuitries by using transcranial magnetic stimulation.

Altered intestinal absorption of L-thyroxine caused by coffee.

Objective: To report eight case histories, and in vivo and in vitro studies showing coffee's potential to impair thyroxine (T4) intestinal absorption.

Design: Of eight women with inappropriately high or nonsuppressed thyroid-stimulating hormone (TSH) when T4 was swallowed with coffee/espresso, six consented to the evaluation of their T4 intestinal absorption. This in vivo test was also administered to nine volunteers.

Neural response to transcranial magnetic stimulation in adult hypothyroidism and effect of replacement treatment.

Purpose: Despite clinical evidences that hypothyroidism is often associated with cognitive dysfunction, affective disorders and psychosis, the effects of thyroid hormone deficiency on the adult brain have been largely unexplored. We investigated the hypothesis that hypothyroidism might affect cortical excitability and modulates inhibitory and excitatory cortical circuits by using Transcranial Magnetic Stimulation.

Materials And Methods: Cortical excitability was probed in 10 patients with overt hypothyroidism and 10 age-matched healthy controls.

Molecular analysis of the PDS gene in a nonconsanguineous Sicilian family with Pendred's syndrome.

Objective: The autosomal recessive Pendred's syndrome is defined by congenital sensorineural deafness, goiter, and impaired iodide organification. It is caused by mutations in the Pendred's syndrome (PDS) gene that encodes pendrin, a chloride/iodide transporter expressed in the thyroid, the inner ear, and the kidney. In this study we performed clinical and molecular analyses in three siblings from a nonconsanguineous Sicilian family who presented with the clinical features of Pendred's syndrome.

Abnormalities of GH secretion in a young girl with Floating-Harbor syndrome.

We present a 9.1-year-old girl of Calabrian (Italy) ancestry, with clinical features (cranio-facial dysmorphism, short stature with delayed bone age and speech delay) suggesting the diagnosis of Floating-Harbor syndrome (FHS). Physical examination showed: height 113.

Extremely high levels of estradiol and testosterone in a case of polycystic ovarian syndrome. Hormone and clinical similarities with the phenotype of the alpha estrogen receptor null mice.

A 19-year-old nulliparous hirsute woman was evaluated for the very high serum levels of testosterone (T) and estradiol (E2) measured in an outside laboratory. Menarche had occurred at 11 years and was followed by regular menses. We confirmed the high levels of T (9-16 ng/ml, nv 0.

Shrinkage of a PRL-secreting pituitary macroadenoma resistant to cabergoline.

Cabergoline decreases both serum PRL levels and size of prolactinomas, including some tumors resistant to other dopamine-agonists. It is common observation that the shrinkage of the adenoma is preceded by suppression of PRL levels. A minority of patients, who do not show a significant decrease of PRL after a short trial with dopamine-agonists, undergoes neurosurgery or radiotherapy.

Thyroid follicular oncogenesis in iodine-deficient and iodine-sufficient areas: search for alterations of the ras, met and bFGF oncogenes and of the Rb anti-oncogene.

To gain insights into the role of iodine deficiency in favoring thyroid tumorigenesis (particularly of the follicular histotype), 22 Sicilian patients with thyroid tumors were selected for having lived permanently in either one of two areas of different iodine availability. Eleven patients (age 46.1 +/- 14.

Myopathy as the persistently isolated symptomatology of primary autoimmune hypothyroidism.

Although disorders of thyroid function may cause a wide range of muscle disturbances, an overt myopathy has been rarely reported as an isolated clinical presentation of hypothyroidism. We observed 10 patients (5 males and 5 females) who had been referred to the department of neurology because of muscular fatigability, myalgia, cramps, or proximal weakness. Laboratory investigation showed that all patients had hypothyroidism due to Hashimoto's thyroiditis (atrophic variant in 9/10).

Expression of the hepatocyte growth factor and c-met in normal thyroid, non-neoplastic, and neoplastic nodules.

We have examined the coexpression of hepatocyte growth factor (HGF) and its receptor (HGF-R or c-met) in an archival series of 63 paraffin-embedded thyroid specimens plus one lymph node metastasis. By immunocytochemistry, we found undetectable expression of both the ligand and the receptor in 10 normal thyroids and 9 nonpapillary malignant nodules [5 follicular carcinomas, 1 poorly differentiated (insular) carcinoma, 3 undifferentiated (anaplastic) carcinomas]. Of 10 non-neoplastic nodules (colloid nodules) and 17 benign neoplastic nodules, 3 of 10 colloid nodules, 2 of 10 follicular adenomas, and 2 of 7 oncocytic adenomas showed a weak but distinct staining (1+ score in a scale from 0 to 4+) of both HGF and c-met in a modest proportion of cells (1% to 3%).

Thyroid iodide transporter: local sequence homologies with thyroid autoantigens.

Here we show the existence of local amino acid (aa) sequence homologies between rat thyroid iodide transporter (Na+/l- symporter or NIS), whose gene was recently cloned, and known human thyroid autoantigens [thyroglobulin (Tg), thyroid peroxidase (TPO) and thyrotropin receptor (TSHR)] NIS sequences corresponding to the fourth (aa 264-282) and fifth extracellular loop (aa 386-414) are 15 to 40% identical and 30 to 60% similar to sequences corresponding to known or putative epitopes of Tg, TPO and TSHR. The sixth extracellular loop (aa 465-485) beared homology (44% identity, 52% similarity) only to a region of Tg which flanks one of its immunodominant domains. Sequences of thyroid autoantigens other than NIS shared homology, especially Tg and TPO.

Thyroid hormone autoantibodies elicited by diagnostic fine needle biopsy.

Based on the knowledge that diagnostic fine needle biopsy of the thyroid (FNAB) results in a prompt increase in circulating thyroglobulin (Tg); we evaluated whether Tg is indeed the postulated antigen for circulating antibodies against thyroid hormones (THAb). Preliminarily, we verified that FNAB causes the release into the bloodstream of iodinated, heterologous, and thus potentially immunogenic, molecules of Tg. Of the initially enrolled 400 patients, 214 had a number of blood drawings sufficient to evaluate over time (before FNAB and 1-3 h, 3 days, 15 days, 30 days, 3 months, 6 months, and 12 months after FNAB) the following parameters: THAb of both IgM and IgG classes, Tg antibodies (TgAb; by a sensitive immunoradiometric assay), and Tg (in the 156 patients who were TgAb negative).

Delayed intestinal absorption of levothyroxine.

We report four female patients with nodular goiter (in two of the four due to Hashimoto's thyroiditis) and one male patient with frank hypothyroidism due to Hashimoto's thyroiditis in whom TSH-suppressive or replacement L-T4 therapy failed to suppress or, respectively, normalize serum TSH. As is typical in our country, our patients took L-T4 15-20 min before a light breakfast. Gastrointestinal or other diseases and drugs known to interfere with the intestinal absorption of L-T4 were not the cause of this failure.

Three new mutations of thyroid hormone receptor-beta associated with resistance to thyroid hormone.

Three novel point mutations at nucleotides 1249, 1282, and 1614 (exons 9 and 10) of the human thyroid hormone receptor-beta gene were observed in six individuals affected by the syndrome of resistance to thyroid hormone. All three mutations occurred in a heterozygous pattern and caused the following changes in the mature form of the receptor protein: Asp322 to Asn, Glu333 to Gln, and Lys443 to Asn, respectively. The first and third point mutations arose in two unrelated families from eastern Sicily, whereas the second concerned an individual from southern Calabria, apparently presenting a sporadic form of the resistance syndrome.