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Biomedical subjects

L Baschieri

Publications and source records attributed to L Baschieri.

At least 73 records · Page 4Linked to original sources

Short term administration of potassium perchlorate restores euthyroidism in amiodarone iodine-induced hypothyroidism.

We studied the effect of potassium perchlorate (KClO4) in patients with hypothyroidism due to amiodarone. The short term administration of KClO4 to six such patients led to prompt restoration of euthyroidism, while the three untreated patients remained hypothyroid for 2-6 months. Since KClO4 inhibits thyroid iodide transport, thereby blocking further entrance of iodide into the thyroid and decreasing intrathyroidal iodide content, amiodarone-associated hypothyroidism is probably secondary to the inhibitory effect of excess intrathyroidal iodine on thyroid hormone synthesis.

Adult↗

Serum thyroid autoantibodies as a risk factor for development of hypothyroidism after radioactive iodine therapy for single thyroid 'hot' nodule.

Hypothyroidism is often observed after radioiodine treatment in Graves' disease, but it is considered a rare complication in single hyperfunctioning thyroid nodule ('hot' nodule). This concept has been recently challenged, but the available data are conflicting. In the present study we therefore assessed the development of permanent hypothyroidism in 126 patients with thyroid hot nodule treated with 131I (180 muCi/g of estimated nodule weight, total dose 5.5-28.9 mCi). Follow-up ranged between 1 to 11 years. Hypothyroidism was observed in 5 (4%) patients, corresponding to a cumulative incidence by life-table analysis of 4.8% ten years after treatment. No relationship was found between the development of hypothyroidism and the size of the nodule or the total amount of administered dose. Fifty-six patients with euthyroid hot nodule at the time of treatment had higher cumulative incidence of hypothyroidism after 10 years (9.7%) than those with toxic adenoma (1.5%) (0.1 greater than P greater than 0.05 by logrank test). When the patients were analyzed according to the presence or absence of serum antithyroglobulin and/or antithyroid microsomal autoantibodies, the prevalence of hypothyroidism after 131I treatment was higher (4/25 = 16%) in patients with significant serum antibody titres (greater than or equal to 1/400 by passive haemagglutination), when compared to that observed in subjects with negative antibody tests (1/101 = 1.0%). Life-table analysis showed in antibody positive patients a cumulative incidence of hypothyroidism after 10 years of 18.0% vs 1.4% in antibody negative patients (P less than 0.001 by logrank test).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Veralipride in the treatment of hot flushes in the menopause].

Thirty-six menopausal women and 18 women with surgically-induced menopause were treated with a daily oral dose of 100 mg of veralipride for a period of 20 days followed by 10 days without therapy. Following 2 or 3 treatment periods, the drug was effective in 27 women from the first group and in 13 women from the second group. Six women had to discontinue therapy because of adverse effects. There was no significant variation in FSH or LH serum levels.

Adult↗

In vitro studies on TSH secretion and adenylate cyclase activity in a human TSH-secreting pituitary adenoma. Effects of somatostatin and dopamine.

We have studied the in vitro TSH secretion and the adenylate cyclase (AC) activity of a human pituitary adenoma surgically removed from a hyperthyroid patient showing high serum TSH levels. The tumor appeared almost homogeneously constituted by cells positive for an anti-TSH-beta antiserum and showing the ultrastructural characteristics of the adenomatous thyrotrophs. Adenoma fragments released in vitro a large amount of TSH (148.4 microU/mg prot/30 min), alpha-subunit (35.5 ng/mg prot/30 min) and TSH-beta (10.1 ng/mg prot/30 min). The effects of somatostatin (GHRIH) and dopamine (DA) on the hormone release have been tested in vitro. Both agents markedly inhibited the release of intact TSH and TSH-beta whereas the release of alpha-subunit was less affected. The two agents were effective at concentrations higher than 10(-8)M. The ability of GHRIH and DA in modulating the AC activity was investigated in membrane fraction preparations. GHRIH inhibited AC at concentrations higher than 10(-7)M. The maximal inhibition was 32% at 10(-5)M. Conversely, DA slightly stimulated AC activity. This effects was not mimicked by the dopaminergic ergot CH 29-717, which was completely ineffective on the enzyme. These results suggest that: 1) in this TSH-secreting pituitary adenoma a normal secretory response to the inhibiting agents (GHRIH and DA) is present; 2) different mechanisms of transduction of the GHRIH and DA signals (cAMP dependent and cAMP independent) could be operating in this tumor.

Adenoma↗

Effects of continuous light and dark exposure on hypothalamic thyrotropin-releasing hormone in rats.

The thyrotropin-releasing hormone (TRH) content in whole hypothalamus was measured by specific radioimmunoassay in rats exposed to a daily light-dark cycle (06:00-18:00 light, 18:00-06:00 dark) and in animals exposed to constant light or constant darkness for 12 days. A nyctohemeral variation of hypothalamic TRH was observed in light-dark exposed animals, while this variation was abolished by exposure either to constant light or constant darkness. These data indicate that any study involving hypothalamic TRH determination should be carried out taking into account the diurnal variation and the effect of environmental light exposure.

Animals↗

Reciprocal changes of serum thyroglobulin and TSH in residents of a moderate endemic goitre area.

Subjects living in iodine deficient areas were reported to have elevated serum thyroglobulin (Tg) concentrations. This finding was interpreted as related to thyroid stimulation. Discrepant results, however, were found when serum Tg concentrations were correlated either with serum TSH or with goitre size. In this study we investigated the relationships between goitre size, serum Tg and serum TSH in 488 unselected adult subjects living in an endemic area of North-Western Tuscany (Garfagnana district). The control group comprised 352 subjects residing in a non-endemic area. In the endemic area a high prevalence of goitre was found (80.1%), thyroid enlargement being slight to moderate in the majority of cases and very large only in six subjects. Serum Tg concentrations increased and serum TSH levels decreased with the size of goitre. Statistical analysis by the chi-square cross correlation test showed that the converse changes of serum Tg and serum TSH in relation to goitre size were highly significant. These findings indicate that the increase of serum Tg occurring in endemic goitrous subjects may be related to factors other than TSH stimulation. Functional autonomy of the thyroid may account for the finding of low serum TSH and elevated serum Tg values in patients with large goitres. The present data do not exclude the possibility that the release of Tg is influenced by TSH stimulation, but indicate that other factors may be responsible for the increased levels of Tg found in endemic goitre.

Adult↗

Serum free thyroxine in patients with T3-toxicosis.

The serum free thyroxine concentration was measured by direct radioimmunoassay in 38 untreated T3-thyrotoxic patients with elevated serum total and free triiodothyronine, normal serum thyroxine and free thyroxine index, no TSH response to TRH, and with clinical evidence of hyperthyroidism. An elevation of circulating free thyroxine values was observed in 58% of the patients, whereas total serum thyroxine concentration was within the normal range. It is suggested, therefore, that T3-thyrotoxicosis should be reserved for patients with elevated serum total T3 and free T3 concentrations and normal serum total T4 and free T4 concentrations. Serum thyroxine-binding globulin concentrations were significantly lower (P less than 0.025) in patients with an elevated serum free thyroxine (18.7 +/- 3.6 micrograms/ml: mean +/- SD) as compared with those in patients with a normal free thyroxine concentration (23.4 +/- 2.6 micrograms/ml). In addition, no daily fluctuations in total and free thyroxine concentration were observed in 6 patients over a 4-8 day period.

Adult↗

TDI-induced oculorhinitis and bronchial asthma.

A case of allergic oculorhinitis induced by toluene diisocyanate (TDI) exposure in a subject who two years later developed bronchial asthma due to TDI is described. A 55-year-old nonatopic spray painter developed symptoms of oculorhinitis two or three hours after direct occupational exposure to polyurethane varnish; at the first examination neither specific nor nonspecific bronchial hyperresponsiveness was present. Two years later the patient, who had remained in his job, developed episodic dyspnea, wheezing, and cough immediately after TDI exposure, with persistence of oculorhinitis; at this time a slight immediate-type response to a specific bronchial provocative test with polyurethane varnish and TDI was observed. Nonspecific bronchial hyperresponsiveness was mild. Specific IgE to TDI-HSA conjugate was present at both the first and second examinations. We conclude that, in some cases, TDI may cause "allergic" oculorhinitis and bronchial asthma, probably with an immunological IgE-mediated mechanism.

Asthma↗

Humoral markers for thyroid carcinoma.

We investigated the usefulness and limits of serum thyroglobulin, serum calcitonin, and serum tissue polypeptide antigen as humoral markers for thyroid carcinoma in 364 patients with papillary, follicular, medullary, and undifferentiated types of thyroid cancer. In agreement with other studies we found that serum thyroglobulin was a specific and sensitive marker for well-differentiated thyroid cancer after total thyroidectomy. Lymph node, lung, and bone metastases were associated with high serum thyroglobulin concentrations, both during and after thyroid-suppressive therapy with L-thyroxine. Serum thyroglobulin determination was superior to whole body scanning in predicting the presence of differentiated metastases, because patients with nonfunctioning metastases and negative whole body scan also had high levels of serum thyroglobulin. Serum calcitonin levels were increased in all patients with active medullary thyroid cancer, confirming the specificity of this marker in detecting tumors arising from parafollicular C-cells. Furthermore, in medullary thyroid cancer serum tissue polypeptide antigen levels were also increased in most patients. This last substance was found to be increased also in undifferentiated thyroid cancer. Of particular interest was the finding of increased serum tissue polypeptide antigen levels in 15 cases of differentiated thyroid cancer, whose metastases underwent a progressive process of "dedifferentiation."

Calcitonin↗

Twenty-four hour radioactive iodine uptake in 35 patients with amiodarone associated thyrotoxicosis.

Amiodarone associated thyrotoxicosis (AAT) occurs in approximately 10% of patients treated with this iodine rich drug in areas of mild iodine deficiency. The thyroid radioactive iodine uptake (RAIU) is usually undetectable or very low in iodine-induced thyrotoxicosis. In the present study, 35 patients with AAT were evaluated. Twelve patients had no thyroid abnormalities by physical exam and all had 24-hr RAIU less than or equal to 4%. In contrast, nine of 11 patients with AAT and diffuse goiters and eight of 12 patients with AAT and nodular goiters had RAIU values greater than 8%. In patients with AAT and goiter it appears possible that the thyroid fails to adapt normally to the excess iodide load, resulting in an inappropriately high RAIU in the presence of excess plasma iodine.

Adult↗

Metastatic medullary and undifferentiated thyroid cancers are not associated with elevated levels of serum thyroglobulin.

It is now well accepted that serum thyroglobulin (Tg) determination is a specific marker of disease activity in well-differentiated thyroid cancer after total thyroidectomy. In this study we examined 15 thyroidectomized patients with metastases from medullary thyroid cancer and 10 patients with metastases from undifferentiated thyroid cancer, to determine whether serum Tg measurement could be useful also in these types of thyroid tumors. In contrast with differentiated thyroid cancer, which had high levels of circulating serum Tg, patients with medullary and undifferentiated thyroid cancer had undetectable or low levels of serum Tg. Thus, serum Tg measurements are not useful in the diagnosis of metastatic disease in these patients.

Calcitonin↗

Effect of 2-deoxy-D-glucose on hypothalamic-pituitary-thyroid axis in rats.

The intraperitoneal administration to rats of 500 mg/kg body weight of 2-deoxy-D-glucose, an analog of glucose which produces intracellular glucopenia with rise in extracellular fluid glucose concentration, is followed by a significant though transient reduction of hypothalamic TRH content, observed at 15 and 25 minutes after drug administration. A subsequent increase in serum thyrotropin followed by that of triiodothyronine concentration was also observed. These findings indicate that the neuroglucopenia induced by 2-deoxy-D-glucose may play a role in the regulating the hypothalamic-pituitary-thyroid axis.

Animals↗

Serum thyroglobulin determinations in the differential diagnosis of congenital hypothyroidism.

The value of serum thyroglobulin (Tg) determination in the differential diagnosis of congenital hypothyroidism was assessed by serum Tg measurements in 14 patients with proven congenital hypothyroidism, in 3 subjects with transient perinatal hypothyroidism, in 3 newborns with congenital thyroxine binding globulin (TBG) deficiency and in 34 normal controls. Serum Tg was undetectable in all 6 cases with thyroid agenesis, normal or moderately elevated in the 4 cases with ectopic thyroid, markedly increased in the 4 cases with dyshormonogenic goiter and normal in the 3 cases with transient hypothyroidism and in the 3 with TBG deficiency. The present data indicate that serum Tg measurements may be useful in the differentiation of athyreotic hypothyroidism from other conditions of congenital hypothyroidism.

Adolescent↗

Serum tissue polypeptide antigen (TPA) in thyroid cancer.

Serum tissue polypeptide antigen, (TPA), carcinoembryonic antigen (CEA), calcitonin (CT) and thyroglobulin (Tg) have been measured by specific radioimmunoassays in 174 patients with various types of thyroid cancer previously submitted to thyroidectomy. Elevated serum TPA concentrations were found in 12 of 13 patients with local invasion or distant metastases from undifferentiated thyroid cancer or thyroid lymphosarcoma, while serum Tg and CEA values were normal or undetectable. In 123 patients with well differentiated thyroid cancer serum TPA was usually normal regardless of the presence or absence of functioning metastases. On the contrary, 14 of 15 patients with "dedifferentiated" metastases from previously differentiated thyroid cancer had elevated serum TPA values, while serum CEA was normal and serum Tg variable. Serum CT was confirmed as the most sensitive marker of metastatic medullary thyroid carcinoma, but elevated serum TPA values were also found in most of these cases. The present data indicate that serum TPA provides a new humoral marker in the follow-up of undifferentiated and "dedifferentiated" thyroid carcinoma and may also be usefully employed as an additional marker for medullary thyroid carcinoma.

Adolescent↗