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Biomedical subjects

E Gardini

Publications and source records attributed to E Gardini.

At least 37 records · Page 2Linked to original sources

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↗

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↗

Prevalence of antibodies reactive with a 64 kDa eye muscle membrane antigen in thyroid-associated ophthalmopathy.

We have determined the prevalences of antibodies reactive with certain pig eye muscle membrane antigens, as determined from SDS-polyacrylamide gel electrophoresis (PAGE) and western blotting, in patients with autoimmune thyroid disorders with or without associated ophthalmopathy. The most frequently detected antibody was that directed against a protein of 64 kDa. Antibodies against this antigen were detected in 33% of unselected patients with ophthalmopathy and in 75% of those with severe, active, orbital inflammation of less than 12 months duration. Such antibodies were detected also in 33% of patients with Graves' hyperthyroidism with no apparent eye disease and in 17% of patients with Hashimoto's thyroiditis with no eye disease but were not detected in patients with nonautoimmune thyroid disorders in 25 normal subjects tested. In the majority of sera showing reactivity with this protein, reactivity with membrane antigens of 55 and 95 kDa also were observed, suggesting that the three proteins were conformationally associated. Cytotoxic antibodies against human eye muscle cells, measured in antibody-dependent cell-mediated cytotoxicity (ADCC), were demonstrated in 37% of patients with ophthalmopathy. There was no significant correlation, in patients with eye disease, between positive ADCC tests and antibodies to the 64 kDa protein, the 64 kDa reactive antibody being found in 50% of patients with positive ADCC and in 35% of those with negative tests. In this study, a clear association has been shown between thyroid-associated ophthalmopathy and the detection, in immunoblotting, of antibodies reactive with a 64 kDa eye muscle membrane antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Relationship between plasma profiles of oxytocin and adrenocorticotropic hormone during suckling or breast stimulation in women.

Oxytocin (OT) administration has been shown to inhibit adrenocorticotropic hormone (ACTH)/cortisol secretion in several experimental conditions. In the present study, the plasma OT responses to suckling in 7 lactating women or to mechanical breast stimulation in 6 normally menstruating women (experimental tests) or to sham stimuli in the same subjects (control tests) were measured and correlated with the simultaneous changes in plasma ACTH/cortisol levels. All women showed similar basal levels of OT, ACTH and cortisol, which remained unmodified after sham stimulation. In contrast, both suckling and breast stimulation produced a significant increase in plasma OT levels and a significant decrease in plasma ACTH concentrations. When OT and ACTH data were considered together, a significant negative correlation was found between the OT increase and the simultaneous ACTH decline. Plasma cortisol levels were lower during suckling or breast stimulation than in control conditions. These data show an inverse relationship between plasma OT and ACTH levels during suckling and breast stimulation in humans, suggesting an inhibitory influence of OT on ACTH/cortisol secretion in a physiological condition.

Adrenocorticotropic Hormone↗

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↗

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↗

Reduced sensitivity to pirenzepine-induced blockade of growth hormone responses to arginine, exercise, and growth hormone-releasing hormone in type I diabetic subjects.

The present study was performed to establish whether the mechanism by which the cholinergic system influences growth hormone (GH) release was altered in type I diabetic patients. Therefore, we investigated in a dose-response fashion the inhibitory effect of the muscarinic cholinergic receptor antagonist pirenzepine on the GH responses to arginine infusion (30 g infused intravenously (IV) in 30 minutes), exercise (bicycle ergometer test at an intensity of 75 W for 30 minutes), or 1-44 GH-releasing hormone (GHRH) (1 microgram/kg in an IV bolus). In a preliminary study, IV injection of 17.5 mg pirenzepine failed to produce modification in the GH response to arginine infusion in both diabetic (N = 4) and normal subjects (N = 4), and to exercise (diabetics, N = 4; normals, N = 4). Therefore, other subjects were tested without and with 20, 25, and 30 mg pirenzepine during arginine (diabetics, N = 7; normals, N = 7) or exercise (diabetics, N = 7; normals, N = 7) tests. Each subject was tested four times. Diabetic patients presented higher GH responses to stimulation with arginine or exercise than normal controls. In both groups, pirenzepine administered at doses ranging from 20 to 30 mg produced a dose-related inhibition of the GH response to arginine and exercise, which was almost complete when 30 mg pirenzepine was administered. However, the percent inhibition produced by 20 or 25 mg pirenzepine in the arginine test and by 20 mg in the exercise test was significantly lower in the diabetic patients than in the normal controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

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↗

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↗

Eye muscle membrane reactive antibodies are not detected in the serum or immunoglobulin fraction of patients with thyroid-associated ophthalmopathy using an ELISA and crude membranes.

We tested sera and purified immunoglobulin (Ig) fractions from patients with autoimmune thyroid disorders (AITD), with and without ophthalmopathy, and normal subjects, for the presence of antibodies reactive with eye muscle membrane antigens in an optimized enzyme-linked immunosorbent assay (ELISA). We found no correlation between ELISA results and the presence or severity of ophthalmopathy in patients with AITD for either serum or Ig, and there were no significant differences between the mean values (+/- SE) for the three groups (AITD with ophthalmopathy, AITD without ophthalmopathy and normals) for either serum or Ig. In contrast Ig from 8 of 19 (45%) patients with thyroid-associated ophthalmopathy reacted with a 64 kDa eye muscle membrane antigen in SDS-polyacrylamide gel electrophoresis and Western blotting, while tests were positive in only one of the 8 patients with AITD without eye disease and in none of the 8 normal subjects. The presence of antibodies to a 64 kDa antigen in immunoblotting did not correlate with the levels of antibodies measured in ELISA. We conclude that the ELISA, incorporating a crude membrane fractions as antigen, is not useful as a clinical test for eye muscle autoantibodies.

Adult↗

Simultaneous inhibition by pirenzepine of the GH responses to GnRH and TRH in insulin-dependent diabetics and in patients with major depression.

The present study was undertaken in order to establish whether muscarinic cholinergic receptors are involved in the anomalous GH response to GnRH in men with insulin-dependent diabetes mellitus and in male patients with major depression. For this purpose, 16 male diabetics, 18 depressed men and 9 normal controls were tested with GnRH (25 micrograms iv) with and without previous treatment with the muscarinic cholinergic receptor blocker pirenzepine (40 mg iv 10 min before GnRH). Additional experiments with TRH (200 micrograms iv 10 min after pirenzepine) were performed in the same subjects and used for comparison between responders to TRH and GnRH. The administration of GnRH stimulated GH release in 12 out of the 16 diabetics and in 8 out of the 18 depressed patients, but not in the normal controls. Control and diabetic non-responders to GnRH did not respond to TRH. In contrast, all diabetic responders to GnRH, except 2, showed paradoxical GH responses to TRH. All depressed responders to GnRH and 3 of the non-responders, were responsive to TRH. The pattern and magnitude of the secretory responses to TRH and GnRH were similar in depressed and diabetic patients. When the effects of GnRH and TRH were restudied in the presence of pirenzepine, neither GnRH nor TRH enhanced the serum concentrations of GH in any patient. These data indicate that a muscarinic cholinergic mechanism is involved in the anomalous responses of GH to GnRH and TRH in diabetic men and in male patients affected by major depression.

Acetylcholine↗

Comparison of methimazole, methimazole and sodium ipodate, and methimazole and saturated solution of potassium iodide in the early treatment of hyperthyroid Graves' disease.

We have evaluated three regimens for the rapid control (10 days' therapy) of thyrotoxicosis in hyperthyroid Graves' disease: methimazole (MMI, 40 mg/day), MMI and sodium ipodate (MMI + Na Ipodate, 1 g/day and MMI and saturated solution of potassium iodide (MMI + SSKI, 6 drops twice daily). When serum T4 and T3 concentrations were analysed as the percent change from pre-treatment values, the following results were observed. Serum T4 concentration decreased in the three treatment groups and the decrease was similar in the MMI and MMI + SSKI groups but significantly lower than in the MMI + Na ipodate group. The serum T3 concentration decreased to the normal range in all seven MMI + Na Ipodate treated patients by the fourth day of treatment and the per cent decrease in serum T3 from pre-treatment values was significantly greater than in the MMI and MMI + SSKI treated patients. The decrease in serum T3 was similar in the latter two groups. Heart rate decreased in all three groups, but the decrease was significantly more in the MMI + Na Ipodate-treated patients. The present findings suggest that the rapid control of hyperthyroid Graves' disease is similar in patients treated with MMI and MMI + SSKI and that the combination of MMI + Na Ipodate is more efficacious since the decrease in serum T3 concentrations and heart rate was significantly greater in the MMI + Na ipodate-treated patients.

Adult↗

Effect of bromocriptine on neurophysin secretion in pregnant women in labour.

In order to determine whether dopamine plays a role in the control of neuropituitary function in pregnant women during labour, blood levels of nicotine (NSN)- and estrogen (ESN)-stimulated neurophysins were measured in 119 women treated orally with placebo (n = 59, control group) or 5 mg bromocriptine, a potent dopaminergic receptor agonist (n = 60, experimental group). Serum samples were taken before drug ingestion (basal sample) and at delivery. The serum basal concentrations of NSN and ESN were similar in both groups of pregnant women in labour. At delivery, serum ESN levels were similar in all women regardless of the treatment, whereas NSN concentrations were significantly lower in the bromocriptine-treated women than in those who were given placebo. In additional experiments the effect of 5 mg bromocriptine on the serum concentrations of NSN and ESN was tested for 6 hours after drug ingestion in 10 healthy, non-pregnant women and in 8 women in the 3rd trimester of pregnancy. Bromocriptine did not modify the circulating levels of NSN and ESN in either of these 2 groups of women. Since NSN and ESN are thought to be associated with vasopressin and oxytocin, respectively, these results indicate that in non-pregnant women and in pregnant women during late pregnancy dopaminergic stimulation with a dopaminergic receptor agonist does not inhibit the release of either vasopressin or oxytocin during rest. In contrast, dopaminergic receptor stimulation appears to play an inhibitory role in the regulation of vasopressin, but not oxytocin secretion in pregnant women in labour.

Adult↗

The effect of diltiazem, a calcium channel-blocking drug, on cardiac rate and rhythm in hyperthyroid patients.

Tachycardia and tachyarrhythmias are frequent in patients with thyrotoxicosis, especially in the elderly. Since myocardial calcium uptake is increased in thyrotoxic rats, the efficacy of the calcium channel-blocking drug diltiazem in decreasing heart rate and the incidence of arrhythmias was evaluated in 11 hyperthyroid patients. All patients were studied with a 24-hour Holter monitor prior to the beginning of sole diltiazem therapy (120 mg given every eight hours), on the tenth day of therapy, and five days after therapy was discontinued. Heart rate significantly decreased by 17% during diltiazem treatment (96.5 +/- 3.7 systoles/min vs 79.9 +/- 3.2 systoles/min [mean +/- SE]) and returned to baseline values five days after the therapy was discontinued (100.7 +/- 3.4 systoles/min). Similarly, the number of premature ventricular extrasystoles per hour was significantly decreased (18 +/- 7 vs 2 +/- 1). In three patients, asymptomatic bouts of supraventricular tachycardia, paroxysmal atrial fibrillation, or ventricular tachycardia disappeared during diltiazem therapy. These findings suggest that calcium-blocking drugs may be extremely useful as adjunctive therapy for thyrotoxicosis in the presence of angina, congestive failure, and tachyarrhythmias.

Adult↗

Dopaminergic regulation of fetal growth hormone (GH) secretion: study with maternal administration of bromocriptine.

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.

Bromocriptine↗