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Reports on the effects of single and multiple doses of methimazole on serum thyroxine and heart rate in hyperthyroid patients. Advantages of using single over divided dose of an antithyroid drug; Preference of methimazole to propylthiouracil; Dependence of antithyroid effectiveness of the thionamides on their ability to inhibit the organification of iodine; Percholrate discharge test to evaluate the degree of inhibition.

Usually differentiated thyroid cancer has a good prognosis and only rarely shows distant metastasis at diagnosis above all the papillary carcinoma. We present the case of a female patient of 66 years old affected by a papillary thyroid carcinoma with a bone metastasis as initial presenting symptom; she was hospitalized for pelvic pain and motor weakness and treated for severe osteoporosis. The patient was submitted to pelvis X-Ray that showed an area of bone loss and cortical irregularities of the right acetabulum, which was compatible with secondary neoplastic lesion but no primary tumor was found. The bone biopsy showed "papillary thyroid carcinoma, follicular variant", so the patient was candidated to a total thyroidectomy.

Background: The association between patients with surgically treatable thyroid disease and patients affected by PHPT is not just accidental., Materials: We report 591 patients who underwent total thyroidectomy in our center. Data, collected during the preoperative period according to our protocol for candidates to total thyroidectomy, included: type of thyroid disease, sex, age, type of surgical procedure, preoperative PTH and plasmatic calcium level. Calcium plasmatic level has been monitored at 24 hours after surgery on day 6 and monthly for 6 months., Results: On 591 cases, PTH above the normal range were present in 19.1% (113 patients), all asymptomatic for PHPT 30 were males (26.6%) and 83 females (73.4%), with a mean age of 62.97 +/- 12.51 years and 57.38 +/- 15.09 years ( p = 0.19). The mean preoperative PTH and calcium plasmatic level were 104.4 +/- 21.96 pg/ml and 119.7 +/- 37.93 pg/ml (p = 0.39) and 9.21 +/- 0.59 mg/dL e 9.37 +/- 0.87 mg/dl (p = 0.45) respectively. Intraoperative exploration proved a pathological parathyroid gland in 12 on 113 cases. In 9 of the 12 patients with parathyroid adenoma, hypocalcaemia developed. It resolved in 7 days for 4 patients and within 30 days for the others. No hypocalcaemia has been recorded at a 6 months follow up for the 97 considered (4 were lost at follow up)., Conclusion: Preoperative PTH measurement for all patients undergoing total thyroidectomy may offer a concrete tool to screen and identify the above-described category of patients, with no additional cost for further radiological investigations, because this class of patients will be submitted to bilateral cervical exploration associated with a total thyroidectomy.

Background: Total thyroidectomy is the treatment of choice for thyroid cancer and for selected benign thyroid conditions. The aging of the general population and the improvements in surgical technique induced an extension of the surgical indications to major thyroid surgery to older patients also on a short stay basis., Methods: From January 2004 to December 2006, 152 patients affected by thyroid carcinoma underwent total thyroidectomy on a short stay basis. We divided our series in 2 groups of patients according to the age (> or < of 65 yrs) and considered the outcome analysing several factors including: ASA score, mean operative time, mean hospital stay, tumour size, and post-operative complications., Results: The groups consisted of: 115 pts with a mean age of 46.81 +/- 11.63 years and 37 pts with a mean age of 74.53 +/- 3.71 years for the younger and older group respectively. The differences in ASA score and hospital stay were statistically significant between the groups (P < 0.007 and P < 0.004); neither postoperative haemorrage nor permanent hypocalcemia was observed. One permanent paralysis of the recurrent laryngeal nerve was noted at 12 months follow up; transient hypocalcemia, which resolved in all cases within 30 days from surgery, was reported in 23 and in 7 patients in the younger and older group respectively., Conclusions: Although a longer length of stay was noted in the older group and possibly related to a higher ASA score and a worse preoperative airways condition, total thyroidectomy for differentiated thyroid carcinoma may be safely carried out in older patients on a short stay basis if performed by an expert staff and in the setting of a multidisciplinary and exhaustive preoperative assessment.

Background: Hypocalcemia is a possible sequela of thyroidectomy; the causes are not fully understood., Methods: We analyzed 804 patients (594 total thyroidectomy, 209 emithyroidectomy) treated in our Institute from January 1995 to December 2000. Serum calcium, ionized calcium, parathyroid hormone (PTH), fosforemia were screened pre- and postoperatively., Results: Hypocalcemia, defined by a serum calcium less than 7.5 mg/dL, occurred in 126 patients (21.2%). In 90.6% of these patients the serum calcium was normal at seven days after thyroidectomy. In two patients we have registered at 180 days after thyroidectomy a permanent hypoparathyroidism., Conclusions: Several factors are important in the incidence of postthyroidectomy hypocalcemia but the inadvertent excision of parathyroid gland, ischemia and injury are the major causes of lowering of serum calcium concentration.

Hypocalcaemia is a possible sequela of thyroidectomy, the causes of which are not fully understood. Today, correct surgical technique is the most important factor in decreasing the incidence of hypocalcaemia. We analysed 1223 patients (930 total thyroidectomies, 293 hemi-thyroidectomies) treated in our institute from January 1995 to July 2003. Serum calcium, ionized calcium, parathyroid hormone and phosphoraemia were screened pre- and postoperatively. Hypocalcaemia, as defined by a serum calcium concentration below 8.5 mg/dL, occurred in 241 patients (25.1%). In 90.9% of these patients, serum calcium was normal 7 days after thyroidectomy. In three patients we registered permanent hypoparathyroidism 180 days after thyroidectomy. We found a statistically significant difference in the incidence of hypocalcaemia between patients treated for benign disease and those treated for malignant disease with a greater incidence in the latter group (P < 0.05). Several factors are important in determining the incidence of post-thyroidectomy hypocalcaemia but the inadvertent excision of the parathyroid gland, ischaemia and injury are the main causes of the lowering of serum calcium concentrations.

We report the experience of the Institute of Surgical Pathology of the University of Parma on three patients with sporadic medullary thyroid carcinoma (MTC). MTC is a tumor of parafollicolor cells origin (C cells). The surgical excision of the thyroid tumor and cervical node metastases is potentially curative. The other therapeutic options are limited. Considerable emphasis has been placed on early diagnosis and surgery for multiple endocrine neoplasia (MEN) related MTC. Genetic screening promises earlier and accurate diagnosis (RET gene mutations are found in MEN).

Iodide-induced hypothyroidism has been observed in subjects treated with compounds with mild antithyroid activity. The hypoglycemic agent tolbutamide belongs to the aminoheterocyclic group, a class of compounds with antithyroid effect. Thus it was thought interesting to study the effect of large doses of iodide on thyroid function in diabetics chronically treated with tolbutamide. Basal thyroid function as assessed by clinical examination and iodothyronine and TSH concentrations was normal in all patients. Furthermore, in diabetics treated with tolbutamide, hormone concentrations were not different from those of patients treated with insulin or diet. Serum T4, T3 and TSH did not show any significant variation throughout the investigation period. Our results suggest that thyroid function is not affected by chronic treatment with tolbutamide even when large doses of iodide are administered.

To investigate the role of dopaminergic pathways on the control of growth hormone (GH) secretion, bromocriptine (BMC), a dopamine agonist drug, was orally administered at the dose of 5 mg to 46 pregnant women during labor whereas 41 received placebo. Maternal blood was obtained before drug administration and at delivery. Cord blood was obtained at delivery. Following the interval of time elapsed between BMC or placebo ingestion and parturition, maternal and cord blood samples were divided in 7 groups for statistical analysis. Cord blood GH resulted significantly higher than the corresponding maternal value (p less than 0.001). No significant change in GH values was observed nor in samples of mothers treated with BMC compared to mothers treated with placebo neither in cord blood samples of the corresponding neonates. These findings indicate that BMC administration does not modify GH secretion in the term fetus.

The effect of oral glucose and arginine infusion on plasma glucose, glucagon, serum insulin, and C-peptide concentrations was evaluated in 16 patients with hyperthyroid Graves' disease and in ten euthyroid age- and sex-matched normal subjects. Basal plasma glucose concentrations were significantly higher in the hyperthyroid patients, but the plasma glucose response following glucose and arginine administration was similar in the two groups. The insulin response was similar in the hyperthyroid and normal subjects after glucose administration and significantly lower during arginine infusion in the hyperthyroid patients. The serum C-peptide response to both glucose and arginine administration was markedly blunted in the hyperthyroid patients, and the plasma glucagon response to arginine infusion was decreased. These results suggest that pancreatic beta and alpha cell secretory function is impaired in hyperthyroidism as assessed by C-peptide and glucagon secretion following oral glucose administration and arginine infusion. The apparent discrepancy between C-peptide and insulin secretion in the hyperthyroid patients following glucose administration might be due to diminished hepatic extraction of insulin or enhanced metabolism of C-peptide.

Thyroxine-binding globulin (TBG) deficiency has been frequently described in single patients and in many families. Most people with abnormal TBG concentrations are euthyroid. Cases of Graves' disease and TBG deficit have rarely been reported. We describe the case of a person with Graves' disease and TBG deficiency. Because of this condition, the patient had a misdiagnosis during part of his clinical history, and therefore underwent unnecessary therapy.

Somatostatin (SRIF) was infused (500 micrograms over 30 min) into 68 pregnant women during labour. As a control, saline was infused into 26 pregnant women. Maternal blood was obtained prior to the infusion and at delivery and cord blood was obtained at delivery. The subjects were divided into 4 groups based upon the interval of time from the termination of SRIF infusion and delivery. There was a marked decrease in cord blood thyrotrophin (TSH) from 0 to 180 min and in cord blood growth hormone (GH) from 0 to 120 min following SRIF infusion. SRIF infusion did not affect cord blood iodothyronine and thyroglobulin concentrations. SRIF administration induced a small but significant (P less than 0.05) decrease in serum GH concentration but had no other effect on maternal hormone values. These studies strongly suggest that SRIF crosses the human placenta and transiently suppresses foetal anterior pituitary TSH and GH secretion.

Metoclopramide (MET), a potent dopamine receptor-blocking drug, or saline was administered to 125 term pregnant women at various time intervals (5-412 min) before delivery. Maternal serum was obtained before and after MET injection. Cord blood was obtained at delivery in MET-treated and saline-treated (control group) women. No significant changes in serum TSH, T4, T3, or rT3 concentrations were observed in maternal or cord blood after MET administration. These results suggest that, in contrast to euthyroid nonpregnant women and men, MET administration does not induce a rise in serum TSH concentration in term pregnant women or in the term fetus. Thus, the dopaminergic inhibitory effect on anterior pituitary TSH secretion may not be an important factor in TSH regulation during pregnancy or in the fetus, or the dose of MET employed may be unable to overcome the dopamine inhibitory effect.

In the adult, dopamine inhibits prolactin (Prl) secretion and less so thyrotropin (TSH) release. Little information is available concerning the role of dopaminergic stimuli in the regulation of TSH and Prl secretion in the term human foetus. The dopamine agonist, bromocriptine (5 mg), or placebo were randomly administered orally to 120 pregnant women during labour. Maternal and foetal cord blood was obtained at parturition and analyzed for Prl, TSH, T4, T3 and rT3 concentrations. Since the time of parturition is unpredictable, maternal and cord blood hormone values were grouped at intervals of time from the time of bromocriptine or placebo administration to delivery. Hormone values were compared between the bromocriptine and placebo groups by two-way analysis of variance (ANOVA). Bromocriptine markedly inhibited maternal serum Prl concentrations compared to values in the placebo treated women (P less than 0.001) and this decrease was more marked as the time interval between bromocriptine administration and delivery increased (P less than 0.001, regression analysis). Cord blood Prl was also significantly lower in newborns whose mothers received bromocriptine (P less than 0.001). Bromocriptine significantly inhibited maternal serum TSH concentrations as compared to values in women treated with placebo (P less than 0.006). In contrast, bromocriptine administration did not affect cord blood TSH concentrations. These findings suggest that bromocriptine crosses the term human placenta and suppresses foetal Prl secretion. In contrast to the small inhibition of TSH secretion in pregnant women, bromocriptine does not affect foetal TSH secretion suggesting that regulation of TSH secretion in the term foetus may not be under dopaminergic control.

In order to study the effect of iodoamide (a contrast medium widely used for urographic and arteriographic studies) on thyroid function, seventeen subjects were studied before and after arteriographic examinations employing this contrast compound. Serum concentrations of T4, T3, rT3 and TSH were not modified during the observation period by the administration of iodoamide. This finding is in contrast with the observation that iopanoic acid and ipodate, used for cholecystographic examinations, can reduce the serum concentrations of T4 and T3 with a concomitant increase in rT3. Therefore, iodoamide is not useful in the treatment of hyperthyroidism.

Thyroid function was studied in a large number of subjects residing in Varsi, a town in the province of Parma, Italy. In this area, endemic goiter associated with moderate iodine deficiency [59 +/- 3 (+/- SE) microgram iodine/g creatinine], as defined by WHO criteria, affects 65% of the population. Serum T4, T3, thyroglobulin (Tg), and TSH concentrations were measured by RIA in 1218 subjects. The TSH response to TRH was determined in 108 subjects selected randomly from the groups with different grades of goiter. No significant change in serum T4 concentrations was found in subjects with different grades of goiter. Serum T3 concentrations were higher in subjects with the larger goiters. Serum Tg concentration progressively increased, and serum TSH progressively decreased with increasing goiter size. The TSH response to TRH was diminished in subjects with larger goiters. The findings of decreasing serum TSH concentrations and blunted TSH responses to TRH as goiter size increased suggest the possibility of autonomous thyroid function in the larger goiters in subjects residing in this area of moderate iodine deficiency.

Serum concentrations of myoglobin, creatine kinase and lactate dehydrogenase were measured in 33 euthyroid, 21 hyperthyroid and 15 hypothyroid subjects. The results showed that myoglobin, creatine kinase and lactate dehydrogenase were increased and decreased in the hypo- and hyperthyroid states, respectively. In addition, the concentrations of myoglobin, creatine kinase and lactate dehydrogenase values were inversely related to both the thyroxine and triiodothyronine concentrations. To study the origin of the increased muscle protein values observed in hypothyroidism, the cardiac isoenzyme fractions were measured; the results obtained support the view that the muscle enzymes are mainly derived from skeletal muscles.

TRH or saline was administered to 214 term pregnant women at various time intervals (8-820 min) before delivery. Cord blood (CB) was obtained, and plasma TSH, T4, T3, rT3, and thyroglobulin concentrations were measured by specific RIA. CB TSH was significantly elevated within 20 min after TRH administration and remained elevated for 180 min. CB T3 rose significantly by 60 min and remained elevated for 820 min. CB T4 was significantly increased from 120 to 820 min after TRH administration. There was no significant change in the CB thyroglobulin concentration. These findings demonstrate for the first time that TRH crosses the human placenta, that the fetal pituitary is responsive to TRH, and that endogenous TSH stimulates the fetal thyroid.

Thyroid hormone serum concentrations, the thyrotropin (TSH) and prolactin (PRL) response to thyrotropin-releasing hormone (TRH) were evaluated in patients undergoing cardiopulmonary bypass (CPB) conducted in hypothermia. During CPB a marked decrease of thyroxine (T4) and triiodothyronine (T3) concentration with a concomitant increase of reverse T3 (rT3) were observed similarly to other clinical states associated with the 'low T3 syndrome'. Furthermore, in the present study elevated FT4 and FT3 concentrations were observed. In a group of patients, TRH administered during CPB at 26 degrees C elicited a markedly blunted TSH response. In these patients, PRL concentration was elevated but did not significantly increase after TRH. The increased concentrations of FT4 and FT3 were probably due to the large doses of heparin administered to these patients. Thus, the blunted response of TSH to TRH might be the consequence of the elevation of FT4 and FT3 in serum, however, other factors might play a role since also the PRL response to TRH was blocked.

The effect of TRH administration to the term pregnant women on the GH response in cord blood (CB) was evaluated in 138 subjects. Previous studies have demonstrated that TRH readily crosses the placenta. TRH (400 microgram) was administered iv to 59 pregnant women just before delivery. CB samples were obtained at delivery and assigned to 6 groups, depending upon the duration of time between TRH injection and CB sampling. The control group comprised 79 pregnant women who received saline. A progressive rise and then a fall in the CB GH concentration were observed after TRH administration. Values were significantly elevated 61-90 min after TRH administration compared to values in saline-treated subjects (19.3 +/- 3.1 vs. 13.1 +/- 0.9 ng/ml; P less than 0.05). The present study is the first report of the effect of TRH on the GH concentration in CB and suggests that TRH stimulates GH release in the fetus.