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Biomedical subjects

R Minelli

Publications and source records attributed to R Minelli.

At least 37 records · Page 2Linked to original sources
PubMed1993

Thyrotoxicosis followed by hypothyroidism in patients treated with amiodarone. A possible consequence of a destructive process in the thyroid.

Amiodarone is an iodine-rich drug used in the treatment of resistant cardiac arrhythmias. Amiodarone-induced thyrotoxicosis (AIT) is well recognized and is generally believed to be due to the excess iodine released from the metabolism of the drug, although amiodarone-associated thyroiditis has occasionally been observed. We report the clinical, laboratory, and therapeutic course of nine patients with AIT. The thyrotoxic phase was often followed by mild hypothyroidism during and after antithyroid drug or corticosteroid therapy. The thyroid was tender to palpation in two patients and a fine-needle aspiration biopsy of the thyroid revealed changes consistent with thyroiditis in three patients who underwent biopsy. These findings strongly suggest that the etiology of AIT, at least in some patients, is due, in part, to drug-induced inflammatory changes in the thyroid, as has been reported to occur in lung, bone marrow, and testes. Thus, the AIT may be due to excess iodine, drug-induced thyroiditis, or a combination of the two. The favorable response of AIT to corticosteroids in occasional patients previously reported also suggests that acute thyroiditis was probably present.

Adult↗
PubMed1993

Sodium ipodate and methimazole in the long-term treatment of hyperthyroid Graves' disease.

A prospective study was conducted to evaluate the effect of prolonged treatment of hyperthryoid Graves' disease with methimazole (MMI) for 12 months or Na ipodate for only 6.6 +/- 1.1 months, since the drug had to be discontinued because of persistent or recurrent hyperthyroidism during treatment. The eight patients who were treated with MMI alone for 12 months became euthyroid, and seven remained in remission for at least 6 months after MMI was discontinued. In contrast, only two of 10 patients treated with Na ipodate alone became euthyroid and remained so during therapy. No ipodate was discontinued in the eight patients who did not respond, and they were then treated with MMI. One patient had recurrent hyperthyrodism after NA ipodate was discontinued, and she was then treated with MMI. MMI was efficacious in treating these nine patients, and all patients were euthyroid by the third month of MMI administration. Five of these nine patients remained euthyroid for at least 6 months after MMI was discontinued, a remission rate that was not significantly different from that observed in the eight patients treated only and initially with MMI (Fisher's Exact Test). There was no significant change in serum thyroid peroxidase antibodies during treatment with MMI alone, Na ipodate alone, or Na ipodate followed by MMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Effects of chronic iodine administration on thyroid status in euthyroid subjects previously treated with antithyroid drugs for Graves' hyperthyroidism.

In view of the adverse effects of the administration of pharmacological quantities of iodine to euthyroid patients with a history of a wide variety of thyroid disorders, it has been suggested that iodine-containing medications and radioopaque dyes containing iodine should be avoided, if possible, in patients with underlying thyroid disease. We have now prospectively studied the effects of pharmacological doses of a saturated solution of potassium iodide (SSKI) on thyroid function in euthyroid patients with a previous history of hyperthyroid Graves' disease successfully treated with antithyroid drugs. Ten euthyroid women (mean age, 56 yr) who had hyperthyroid Graves' disease successfully treated with methimazole 36.4 +/- 4.7 months earlier were evaluated before, during, and after the administration of 10 drops SSKI daily for 90 days. The following thyroid function tests were obtained: serum T4, T3, TSH, TSH receptor antibody (TSH-RAb), and antithyroid peroxidase antibody (AbTPO) concentrations; TRH tests; and iodine perchlorate discharge tests. Serum T4, T3, basal and TRH-stimulated TSH, and TSH-RAb values were normal before SSKI administration, but serum AbTPO levels were markedly positive in 7 and iodine perchlorate discharge tests were positive in 4 of these 10 women. During SSKI administration, basal and TRH-stimulated serum TSH values increased above normal in 2 women with normal serum T4 and T3 concentrations; thyroid hormone values and TRH tests were normal in the other 8 patients and similar to values observed in 4 euthyroid women without a history of thyroid disease given SSKI. Serum AbTPO increased slightly, but significantly, during SSKI administration in the 7 women with positive values at baseline (P < 0.05). TSH-RAb remained undetectable. After SSKI withdrawal, the 10 women were reevaluated 60 and 120 days later. Two women developed a blunted TSH response to TRH, but normal serum T4 and T3 concentrations, and 2 women developed overt hyperthyroidism, with undetectable basal and TRH-stimulated serum TSH and elevated serum T4 and T3 concentrations, requiring methimazole therapy. All values in the remaining 6 women were similar to those present before SSKI administration. These results suggest that some euthyroid patients with a history of antithyroid drug therapy for Graves' disease may develop thyroid dysfunction during and after excess iodine administration. The development of subclinical hypothyroidism during SSKI administration was not clinically important, but the occurrence of overt hyperthyroidism after SSKI was discontinued did require antithyroid drug therapy. It is advisable, therefore, to avoid iodine-containing substances in euthyroid patients with a history of antithyroid drug therapy for Graves' disease.

Antithyroid Agents↗
PubMed1992

Subclinical hypothyroidism, overt thyrotoxicosis and subclinical hypothyroidism: the subsequent phases of thyroid function in a patient chronically treated with amiodarone.

In a patient chronically treated with amiodarone, subclinical iodine-induced hypothyroidism occurred as a result of excess iodine released from the amiodarone molecule. The patient was maintained on amiodarone and developed thyrotoxicosis as a result of a destructive process into the thyroid follicles. Amiodarone was withdrawn and methylprednisolone and methimazole treatment was started with resolution of the thyrotoxic phase. Months later, off therapy, the patient developed subclinical hypothyroidism. This is the first description of hypo- and hyperthyroidism in the same patient caused by amiodarone therapy. This unusual observation suggests that patients treated with amiodarone are at risk to develop hyperthyroidism even if they show laboratory findings consistent with hypothyroidism.

Amiodarone↗
PubMed1992

Iodine-induced subclinical hypothyroidism in euthyroid subjects with a previous episode of amiodarone-induced thyrotoxicosis.

Amiodarone-induced thyrotoxicosis (AIT) occurs most frequently in patients with underlying thyroid disease and is generally believed to be due to the iodine contamination of amiodarone and iodine released by the metabolism of the drug. We and others have suggested that the thyrotoxicosis may also be secondary to amiodarone-induced thyroiditis. To further determine the etiology of AIT, we administered large doses of iodides [10 drops saturated solution of potassium iodide (SSKI) daily] to 10 euthyroid patients long after an episode of AIT believed to be due at least in part to amiodarone-induced thyroiditis. Six of these 10 patients had an abnormal iodide-perchlorate discharge test before SSKI administration, indicating a subtle defect in the thyroidal organification of iodide. During SSKI administration, 6 patients developed marked iodine-induced basal and/or TRH-stimulated serum TSH elevations, 2 had suppressed basal and TRH-stimulated TSH values, and 2 had normal TSH responses compared to SSKI-treated euthyroid subjects with no history of amiodarone ingestion or thyroid disease. Serum T4 and T3 concentrations remained normal and unchanged during SSKI administration in both the AIT patients and control subjects. These results strongly suggest that excess iodine may not be the cause of the hyperthyroidism associated with amiodarone therapy, especially in those patients with probable amiodarone-induced thyroiditis. Furthermore, like patients with a previous history of subacute thyroiditis and postpartum thyroiditis, the present results suggest that some patients with a previous history of AIT may be at risk to develop hypothyroidism when given excess iodine.

Amiodarone↗
PubMed1992

Prevalence of anti-thyroid peroxidase antibodies in serum in the elderly: comparison with other tests for anti-thyroid antibodies.

Autoimmune thyroid disease, especially chronic thyroiditis, is prevalent in elderly women and is probably the major cause of hypothyroidism in this population. The reported prevalence of chronic thyroiditis is variable, depending on the area of residence and the method(s) used to detect the presence of anti-thyroid antibodies. The recent finding that thyroid peroxidase (TPO) is the antigen for the thyroid anti-microsomal antibody (AbM) has resulted in the development of sensitive radioimmunoassays (RIA) to detect the presence of AbTPO. We have determined the prevalence of AbTPO (by RIA) in sera from 342 elderly subjects, 248 women and 94 men (mean age 80 years) residing in Reggio Emilia, Italy, and compared the results with other methods for detecting anti-thyroid antibodies, including anti-thyroglobulin (AbTg) and AbM measured by passive hemagglutination (PH) of tanned erythrocytes, and AbM measured by RIA. The prevalence of positive AbTPO was 2.3% in the men and 10.2% in the women, only slightly higher than the prevalence of AbM. However, in the antibody-positive sera, the mean value for AbTPO was approximately 20-fold greater than the upper limit of the normal range, whereas the mean value for AbM was only threefold greater. The prevalence of positive titers for AbM and AbTg measured by PH was far lower, 1.2% and 3.2%, respectively, and those sera weakly positive for AbM and AbTg by PH were strongly positive for AbTPO by RIA. AbTPO RIA may be more useful than AbM and AbTg hemagglutination and AbM RIA for detecting the presence of autoimmune thyroid disease.

Aged↗
PubMed1991

Postpartum thyroid dysfunction in an Italian population residing in an area of mild iodine deficiency.

We have evaluated the occurrence of postpartum thyroid dysfunction (PPTD) in a group of 372 women residing in area of mild iodine deficiency. Thyroid function and autoimmune status were evaluated by means serum T4, T3, TSH measurement and detecting the presence of positive antithyroglobulin antibodies (AbTg), antimicrosomal antibodies (AbM) and thyroid-peroxidase antibodies (AbTPO) titers in women at parturition, at 1, 3, 6 and 12 months postpartum. New onset transient hypothyroidism occurred in 6.4% of women whereas transient thyrotoxicosis in only 1.8% of women. Transient hypothyroidism was not preceded by thyrotoxicosis as indicated by thyroid function tests and serum Tg concentrations. At parturition, the positivity of AbM and AbTPO titers and the presence of goiter appeared to be a risk factors for the development of PPTD.

Antibodies↗
PubMed1991

Thyroid function evaluation by different commercially available free thyroid hormone measurement kits in term pregnant women and their newborns.

Evaluation of thyroid status by measurement of free thyroid hormone concentrations seems particularly helpful in conditions with altered serum binding proteins. In pregnancy, a condition of increased thyroxine binding globulin, serum free thyroxine (FT4) and free triiodothyronine (FT3) concentrations have been reported to be normal, increased or decreased. In the present study we have measured serum total and free thyroid hormone concentrations in pregnant women, their newborns and nonpregnant women. Serum FT4 and FT3 concentrations have been measured with 10 different commercially available kits and the results obtained have been compared. Serum total thyroid hormone concentrations in pregnant women were significantly higher than in their newborns and in nonpregnant women. Maternal serum FT4 concentrations measured with the different kits were always significantly lower than values in nonpregnant women. Furthermore, with one kit, the mean maternal serum FT4 concentration was below the normal range and with many kits, a large number of maternal serum samples had serum FT4 concentrations below the normal range. With all kits, except two, neonatal serum FT4 concentrations were higher than values in their respective mothers and, in general, lower than values in nonpregnant women. Serum FT3 concentrations in nonpregnant women were in the normal range, except with one kit, in which the mean serum FT3 concentration was below the normal range. Serum FT3 concentrations in newborns resulted markedly lower than in parturient and in non pregnant women. With almost all kits, serum FT3 values were below the normal range in many maternal samples. With one kit, maternal serum FT3 concentrations resulted higher than in nonpregnant women, whereas with the other kits serum FT3 concentrations were lower.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Impaired intrathyroidal iodine organification and iodine-induced hypothyroidism in euthyroid women with a previous episode of postpartum thyroiditis.

Postpartum thyroiditis (PPT) is common and occurs in 1.7 to 16.7% of pregnant women, depending upon the study population. Most of these women develop transient hypothyroidism and thyroid function usually returns to normal. We have studied 11 euthyroid women with a previous history of PPT to determine the incidence of subtle defects in thyroid function measured by iodide-perchlorate (I-ClO4) discharge tests and TRH tests and to determine whether these women would develop iodide-induced hypothyroidism. Seven (64%) had positive I-ClO4 discharge tests and 5 (46%) had an abnormally high TSH response to TRH. Thyroid antimicrosomal and antithyroid peroxidase were positive in 8 women (73%) with a previous episode of PPT. The administration of pharmacological amounts of iodide (10 drops of saturated solution of potassium iodide daily) for 90 days to these 11 women resulted in elevated basal and TRH stimulated serum TSH concentrations in 8 (72.7%) compared to TSH values during iodide administration to women who had never been pregnant. Antimicrosomal and antithyroid peroxidase concentrations did not change during iodide administration. These findings strongly suggest that euthyroid women with a previous episode of PPT have permanent subtle defects in thyroid hormone synthesis and are inordinately prone to develop iodide-induced hypothyroidism, similar to findings previously reported in euthyroid subjects with Hashimoto's thyroiditis, with a previous episode of painful subacute thyroiditis, or previously treated with radioactive iodine or surgery for Graves' disease.

Adult↗
PubMed1991

[Activity of natural fatty acids on erythrocyte osmotic resistance].

The aim of the present study was to assess the influence on the functional characteristics of the erythrocyte membrane of adding in vitro different natural fatty acids to blood taken from normal subjects. Blood samples were collected without stasis from healthy volunteers, anticoagulated with heparin or EDTA and incubated at 37 degrees C for 60 min with the different fatty acids at concentrations ranging between 1 x 10(-4) and 3 x 10(-2) molar. Two ml of blood were used for each test. The treated blood was added to graded solutions of NaCl (0.90-0.20 g/dl) at a ratio of 100 microliters/5 ml of solution. The suspensions were kept at room temperature and centrifuged for 10 min at 2000 g, in order to accelerate the sedimentation of the erythrocytes which had not been broken down and so as to obtain a clear supernatant for spectrophotometry of the dissolved haemoglobin. Readings were compared with those obtained from blood samples which had been completely haemolyzed by suspension in distilled water. Results obtained with the blood samples prepared with the fatty acids were compared with control samples from the same donor, also incubated at 37 degrees C for 60 min. Preincubation of the erythrocyte with butyric or caproic or oleic acid at concentrations ranging between 5 and 20 millimolar, provoked a clear deterioration of the osmotic resistances of the erythrocytes, in proportion to the concentration of the fatty acid used. The osmotic insult was systematically more effective in those samples anticoagulated with EDTA than those treated with heparin.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticoagulants↗
PubMed1990

Chronic treatment with a long-acting somatostatin analogue in a patient with intestinal carcinoid tumor: occurrence of cholelithiasis.

The long-acting somatostatin analogue SMS 201-995 has been used efficaciously in the therapy of metastatic carcinoid tumor, vasoactive intestinal peptide producing islet cell carcinoma, acromegaly, and TSH secreting pituitary tumors. We report the development of a gallstone in a patient treated for 23 months with a long acting somatostatin analogue for a metastatic carcinoid tumor. Symptomatic improvement and a reduction in the urinary excretion of 5-hydroxyindoleacetic acid occurred. There was no evidence of a gallstone on ultrasound and CT scan of the abdomen prior to somatostatin therapy. A progressively enlarging, asymptomatic gallstone developed during therapy.

Carcinoid Tumor↗
PubMed1990

Iodine-induced hypothyroidism in euthyroid subjects with a previous episode of subacute thyroiditis.

The effects of the administration of pharmacological quantities of iodide on thyroid function in 18 euthyroid patients with a previous history of painful subacute thyroiditis (SAT) were evaluated, and the results compared to those of iodide administration to 12 euthyroid patients with a previous history of thyroid surgery (TX) for benign nodular thyroid disease. After baseline thyroid function tests, saturated solution of potassium iodide (SSKI; 10 drops; 300 mg iodide) was administered daily for 120 days, and serum T4, T3, and TSH concentrations were assessed 15, 30, 60, 90, 120 days and 2-4 months after SSKI was discontinued. Iodide perchlorate discharge tests were carried out before SSKI administration, and TRH tests were performed on the last day of iodide administration. Two SAT subjects developed clinical evidence of hypothyroidism with markedly elevated serum TSH concentrations, and SSKI was discontinued on days 60 and 90, respectively. Thirteen of 18 SAT patients had at least 1 abnormal thyroid function test (iodide perchlorate discharge test, elevated serum TSH concentration, and abnormal TSH response to TRH) compared to 2 of 12 TX patients. These findings strongly suggest that euthyroid subjects with a previous history of SAT are prone to develop iodide-induced hypothyroidism, suggesting that subtle abnormalities in the thyroid organification of iodide and subsequent thyroid hormone synthesis persist years after the episode of SAT.

Analysis of Variance↗
PubMed1990

Thyrotropin releasing hormone does not stimulate prolactin release in the preterm human fetus.

Previous studies have suggested that fetal PRL secretion does not respond to stimuli such as TRH, metoclopramide, and cimetidine. It was postulated that the lack of response to TRH could be due to the possibility that, in the term fetus, lactotropes secrete PRL maximally and would be unresponsive to further stimulation. In order to study this hypothesis, 200 micrograms TRH or saline were administered to preterm pregnant women in labor. Maternal blood was obtained before TRH and saline administration. Maternal and cord blood were obtained at parturition. PRL, TSH, T4 and T3 concentrations were measured in all sera. TRH administration induced a significant increase in maternal serum PRL, TSH and T3 concentrations. In the cord blood of newborns whose mothers received TRH, serum TSH, T4 and T3 concentrations were significantly higher than in cord blood of newborns whose mothers received saline. Cord blood serum PRL concentrations were unchanged after TRH administration. This latter finding suggests that fetal lactotropes do not respond to TRH in the preterm fetus. Desensitization of fetal PRL secreting cells to TRH stimulation and/or the inhibitory effect of elevated fetal circulating corticosteroids on TRH-induced PRL secretion may explain the absent PRL response to TRH during fetal life.

Female↗