TSH and prolactin secretions in Hashimoto's thyroiditis following withdrawal of thyroid hormone therapy

Changes in the pituitary-thyroid axis in patients with Hashimoto's thyroiditis following withdrawal of thyroid suppressive therapy were analyzed. The group of patients with thyroid adenoma served as control (group I). Patients with Hashimoto's thyroiditis were divided into 2 groups on the basis of serum TSH levels 8 weeks after discontinuing the exogenous thyroid hormone (group II, less than 10 microunits/ml; group III, more than 10 microunits/ml). During treatment with L-T4(200 micrograms/day) or L-T3(50 micrograms/day), there was no significant difference in serum T4-I and T3 levels among the three groups. Following L-T4 withdrawal, basal serum TSH levels were higher at 2 to 8 weeks in groups II and III than in group I. Serum TSH response to TRH was greater at 4 to 8 weeks in groups II and III than in group I. Following L-T3 withdrawal, basal serum TSH levels were higher at 1 and 2 weeks in group II than in group I, while those of group III were consistently higher during the study. Higher TSH responses to TRH were observed at 1 to 8 weeks in groups II and III. Neither basal nor TRH-induced prolactin (PRL) secretion differed significantly among the three groups. We have demonstrated that pituitary TSH secretion in patients with Hashimoto's thyroiditis is affected more by withdrawal of thyroid hormone therapy than in patients with thyroid adenoma. In addition, the present findings suggest a difference between the sensitivity of thyrotrophs and lactotrophs in Hashimoto's thyroiditis after prolonged thyroid therapy is discontinued.     

Increased thyroidal T4/T3 ratio in nodular and paranodular tissues of nontoxic goiter following suppressive treatment with thyroid hormones

The effect of suppressive treatment with thyroid hormones on thyroidal iodothyronines and T4/T3 ratio in nodular and paranodular tissues was investigated in 12 patients with nontoxic goiter. Results were compared to those from 11 nontreated patients. Continuous thyroid hormone administration produced a significant increase in thyroidal T4 and T4/T3 ratio in nodular tissues while T3 remained unchanged. In paranodular tissues a significant rise of T4/T3 ratio, an insignificant increase in T4 and a decrease in T3 were observed following the administration of thyroid hormones. The results are very similar to those obtained in paranodular tissue of autonomously functioning thyroid nodule, and are probably the consequence of suppressed TSH secretion, as TSH predominantly stimulates the synthesis of T3 and/or thyroidal T4 monodeiodination.     

Iodine in contrast agents and skin disinfectants is the major cause for hypothyroidism in premature infants during intensive care

In 51 sick newborns the influence of two different nonionic, iodine-containing contrast agents, Amipaque (group 1) and Omnipaque (group 2) and of long-term treatment with polyvinylpyrrolidone-iodine (PVP-I) (group 3) on thyroid function was studied. In the dose given, freshly dissolved Amipaque releases roughly 100 micrograms 'free' iodide/kg body weight; this release may be even higher in the solubilized agent Omnipaque because of increased breakdown. Urinary iodine excretion was elevated in all groups on day 5 after iodine exposure. In group 1, which included 17 term newborns, the median TSH level was normal after 5 days and 2 weeks, only 1 case of transient hypothyrotropinemia was observed; T4 and T3 median levels were in the lower range of normal. In groups 2 and 3, which included 8 preterm infants of 15 newborns and 9 preterm infants of 19 newborns, respectively, the median TSH values were elevated and T4 and T3 levels were very low. Hypothyroidism was diagnosed in 6 of the 8 preterm and in 1 of the 7 term newborns of group 2. In group 3, 7 of the 9 preterm and 3 of the 10 term newborns reacted with hypothyroidism. Eight preterm and 3 term newborns had to be substituted with thyroxine. The thyroid function of term newborns was less affected by Amipaque or Omnipaque than by PVP-I. The data show that preterm infants are very sensitive to an iodine load.     

10 years of successful treatment with dextrothyroxine in a girl with TSH-induced hyperthyroidism.

14 years ago, a 5.7-year-old healthy girl was treated with desiccated thyroid for a goiter and elevated TSH levels. The goiter disappeared and TSH levels were normalized. However, hyperthyroidism appeared. Without therapy, the goiter reappeared and hyperthyroidism aggravated. Based on hormone values, TSH-induced hyperthyroidism was diagnosed. After exclusion of neoplastic TSH secretion, treatment with dextrothyroxine (DT4) was initiated at age of 10 years and continued during the last 10 years (except for short periods). The girl became euthyroid, has no goiter and normal TSH values. Since thyrotrophs and peripheral tissues are probably normally sensitive to T4, we postulate that her hypothalamopituitary-thyroid control is operating on a higher set point level for T4.     

A case of the syndrome of inappropriate secretion of TSH.

A girl aged 4 years with goiter and accelerated physical and skeletal growth was found to be hyperthyroid on the basis of elevated serum thyroid hormone level, nevertheless both the basal TSH and TSH responsiveness to TRH were maintained within the normal range. Serum TSH was suppressed by exogenous T3 and dexamethasone administration, but not significantly changed after propylthiouracil (PTU) treatment. The diurnal rhythmicity of anterior pituitary hormones was preserved with the high nocturnal peak of TSH and prolactin. Clinically, neither thyrotoxic signs nor evidences of pituitary tumor were observed. Her accelerated growth and elevated thyroid hormone level appeared to be induced by inappropriate secretion of TSH. In view of the literature, this is the first case of the syndrome of inappropriate secretion of TSH excluding the neoplastic origin in Japan.     

Thyroid hormone profiles in goitrous and non-goitrous subjects seen in an endemic goiter area of the Central African Republic]

In the present study T3, T4, TSH serum concentrations were measured in 166 subjects whose goiter grading was ascertained according to WHO classification; 39 of them had no goiter (grading 0), 127 were goitrous with a grading comprised between 1a and 4. The two samples were composed by Males and Females of various ages whose choice was strictly predetermined by random numbers. The median ages of 127 goitrous and 39 non goitrous subjects were respectively 23.5 years and 33.5 years; 30 Males and 5 Females were in the first group; 58 Males and 69 Females in the second. They lived in the Ouham region of Centro African Republic where some of the Authors ascertained a severe goiter endemia due to iodine deficiency and manioc consumption as staple food. All the values of T4 and TSH of the two group of subjects, were significantly different from the control values (p less than 0.01) excepting T3. Goitrous subjects had T4 value lower than non goitrous subjects (p less than 0.05). The subjects of each group were distributed in the four subsequent subgroups: A) with T3, T4, TSH in the normal range; B) with elevated TSH and T3 and T4 in normal range; C) with elevated TSH, subnormal T4, and T3 in normal range; D) with elevated TSH and subnormal T3 and T4. From fig. 1 it can be seen that the 79.5% of goitrous subjects had a supranormal TSH (subgroups B + C + D) and 40.7% of them had a subnormal T4 (subgroups C + D).(ABSTRACT TRUNCATED AT 250 WORDS)     

Thyroid function and antimicrosomal antibody during the course of silent thyroiditis

The thyroid function and antithyroidal antibody were studied in 17 patients with silent thyroiditis unrelated to pregnancy. The antimicrosomal hemagglutination antibody (MCHA) was negative in ten of them (group I) and was positive in seven (group II). At one month after the thyrotoxicosis, thyroid function became normal in both groups. At two months after the onset of thyrotoxicosis, in group I T4 (8.1 +/- 1.8 micrograms/dl, Mean +/- SD), T3 (113 +/- 25 ng/dl) and TSH were normal. At that time T4 (2.8 +/- 2.2 micrograms/dl) was significantly decreased (p less than 0.001) compared with those of group I and the levels of TSH were strikingly increased in 6 patients in group II. The level of T3 (96 +/- 29 ng/dl) in group II was not different from that of group I. Therefore MCHA was negative in patients who did not develop hypothyroidism and MCHA was positive in patients who developed hypothyroidism. The development of hypothyroidism two months after thyrotoxicosis and positive MCHA are correlated. The Tg was elevated in 7 out of 13 patients (54%) with negative antithyroglobulin hemagglutination antibody and in the remainder was normal during thyrotoxicosis. The discrepancy between the level of Tg and thyroid hormones was discussed.     

Pituitary-thyroid axis reactivity to hyper- and hypothyroidism in the perinatal period: ontogeny of regulation of regulation and long-term programming of responses.

To evaluate the role of perinatal thyroid status in the development of pituitary-thyroid axis regulation, we administered triiodothyronine to newborn rats for the first five days postpartum to achieve hyperthyroidism, or propylthiouracil perinatally to rat dams and pups from gestational day 17 through postnatal day 5 to achieve hypothyroidism. Plasma T4, T3, and TSH levels were determined from birth through 50 days postpartum. Administration of exogenous T3 produced the expected immediate suppression of plasma T4 and TSH, with recovery toward normal values beginning within days of discontinuing the T3 regimen. Plasma T3 values were markedly elevated during the period in which T3 was being given, but subsequently became subnormal, with deficits persisting into young adulthood. With the PTU regimen, plasma T4 and T3 levels were markedly suppressed through postnatal day 10, rose over the ensuing two weeks, but nevertheless showed significant deficits into adulthood. TSH levels in the immediate neonatal period were subnormal in the PTU group, despite the marked lowering of circulating thyroid hormones; TSH then rose dramatically to levels four times normal, subsiding to control values by the end of the first month. These results suggest that a critical period exists in which regulation of pituitary-thyroid axis function is programmed. During this phase, TSH secretion can be suppressed by excess thyroid hormones, but cannot be increased by hormone deficiencies. Perhaps more importantly, perinatal thyroid status "programs" its own future reactivity, so that early hypothyroidism results in reduced T4 and T3 levels in adulthood, despite normal levels of TSH.     

甲状腺激素对胸腺上皮细胞CK19蛋白表达的影响

目的探讨甲状腺激素对胸腺的发育的影响及可能的机制。方法将12只怀孕4d的大鼠随机分成A组和B组,A组正常饮水,B组孕鼠供以含有0．02％甲巯咪唑的饮水制备仔鼠甲状腺功能低下动物模型,将A组的仔鼠随机分成对照组和甲状腺素钠组,将B组的仔鼠随机分成甲低组和甲低＋甲状腺素钠组。甲状腺素钠组和甲低＋甲状腺素钠组于出生后15d给予腹腔注射甲状腺素钠（0．5mg／kg体重,1次／d）,连续给药25d。所有动物于出生后40d麻醉处死,测定仔鼠的胸腺重量及脏器指数;采用放射免疫技术测定仔鼠血清中三碘甲状腺原氨酸（triiodothyronine,T3）、四碘甲状腺原氨酸（tetraiodothyronine,T4）、促甲状腺激素（thyroid—stimulating hormone,TSH）水平,免疫组织化学技术检测胸腺上皮细胞细胞角蛋白19（cytokeratin 19,CK19）蛋白的表达量。结果与对照组比较,甲状腺素钠组仔鼠血清中T3、T4显著升高,TSH减少,胸腺重量增大;甲低组仔鼠血清中T3、T4明显降低,TSH显著增高,胸腺重量降低,胸腺上皮细胞CK19蛋白表达减少。与甲低组比较,甲低＋甲状腺素钠组仔鼠血清中T3、T4升高,TSH降低,胸腺指数增大,胸腺上皮细胞CK19蛋白的表达明显增多。结论甲状腺激素可以通过影响胸腺上皮细胞CK19的表达量,使胸腺发育或退化。     

Low T3 syndrome in cancer patients in relation to weight loss, intravenous hyperalimentation therapy and age

In order to investigate the relation of weight loss and intravenous hyperalimentation therapy to low T3 syndrome, serum T3, T4. rT3 and TBG were determined by radioimmunoassay in 105 cancer patients. The cancer patients were classified into 3 groups, Group I, II and III depending on the grade of weight loss, ranging up to a 5% change in weight loss from a healthy condition, from 5 to 9%, and more than 10%, respectively. Cancer patients under age 59 showed no significant difference in serum T3, T4, rT3 and TBG among these 3 groups. However serum T3 and T3/T4 in cancer patients at age 60 and over were significantly reduced in group III, compared to groups I and II. Serum rT3 values were significantly elevated in group III of elderly cancer patients. The incidence of low T3 syndrome in group III of elderly cancer patients was also significantly higher than in groups I and II. In three out of 5 cancer patients with low T3 syndrome, serum T3 values increased after the intravenous hyperalimentation therapy, whereas no significant change in serum T3 values was observed in two patients who died within one day after the final examination. It is concluded that weight loss produced different effects on peripheral conversion of T4 to T3 between cancer patients under age 59 and over age 60 and glucose plays an important role in the pathogenesis of low T3 syndrome except cases with very poor prognosis.     

Influence of radioactive contamination and iodine prophylaxis after the Czernobyl disaster on thyroid morphology and function of the Poznan region]

The radioactive contamination of Poznań Region was recognized after Chernobyl accident as average. The predicted values of minimal (inhalation) and maximal (inhalation and ingestion) committed dose equivalent to the thyroid varied from 2.5 (min) to 24.7 (max) mSv in different groups of adults and children. To follow up the results of iodine prophylaxis and some aspects of possible thyroid gland morphological and functional changes 11086 persons were carefully investigated clinically and biochemically. Among these 11086 persons were 42.6% males and 57.4% females both adults from 17 till 40 year and children up do 16 years. The following parameters were reviewed: pregnancy, time of residence in the region, thyroid abnormalities, family history concerning thyroid diseases, iodine intake in April and May 1986 with possible side effects, changes in the thyroid size observed before and after 1986, degree and kind of thyroid enlargement, serum concentration of T3, T4, TSH, ATMA and ATG titre and finally the effectiveness of thyroid blockade at 24, 48 and 72 h after ingestion of Lugol's solution. Side effects of the ingestion of potassium iodide from 30-70 mg were observed in 153 cases, 36 of them consulted medical doctors but in no case the side effects (dominated by vomiting) threatened the life. In the investigated group were 144 pregnant women. Majority, because 88% of them delivered the baby on or after time and 6.9% before time, 4.9% of natural abortions were noted but non artificial. In the group of children thyroid gland abnormalities before 1986 were reported in 3 cases in 23 after 1986 it is after Chernobyl accident. This information is interesting but needs more precise analysis of different dependencies occurring. The data obtained indicated the existence in Poznań. Region the goiter endemy because 27.5% of investigated children and adults had goiter classified as grades O-B, I, II and III. The elevation or diminution of T3 values were noted in 1164 cases, for T4 in 418 cases and for TSH in 1412 cases. The presence of antimembrane and antithyroglobulin antibodies were observed in 303 cases. All persons with changes observed in thyroid morphology and function are periodically controlled and the results will be published separately. The investigations performed and results presented concern the early aspects of radioactive contamination and effects of iodine prophylaxis. The answer regarding late effects including thyroid cancer needs further multi year studies for which the clinical material investigated in different parts of Poland and well documented should be used as model group for further periodical studies.     

Trace elements status in multinodular goiter

Importance of iodine and selenium in thyroid metabolism is well known, but the roles of other essential trace elements including copper, zinc, manganese and iron on thyroid hormone homeostasis remain unclear. The aim of this study was to investigate the status of those trace elements in benign thyroid diseases and evaluate possible links between trace element concentrations and thyroid hormones.The study group was composed of 25 patients with multinodular goiter. Concentrations of thyroid hormones (plasma-free thyroxine, FT₄; free triiodothyronine, FT₃; and thyrotropin, TSH), selenium, copper, zinc, manganese and iron in plasma, and urinary iodine were determined. The results were compared with those of a healthy control group (n=20) with no thyroid disorder.A mild iodine deficiency was observed in the patients with multinodular goiter whereas urinary iodine levels were in the range of “normal” values in healthy controls. All patients were euthyroid, and their thyroid hormone concentrations were not significantly different from the control group. Plasma selenium, zinc and iron concentrations did not differ from controls, while copper and manganese levels were found to be significantly higher in the patients with multinodular goiter indicating links between these trace elements and thyroid function and possibly in development of goiter. Besides iodine, there was a significant correlation between plasma copper concentration and FT₃/FT₄ ratio.     

Plasma free fatty acids, inhibitor of extrathyroidal conversion of T4 to T3 and thyroid hormone binding inhibitor in patients with various nonthyroidal illnesses.

In order to clarify the role of free fatty acid (FFA) in thyroid hormone abnormalities in patients with nonthyroidal illness, thyroid function, FFA, inhibitor of extrathyroidal conversion of T4 to T3 (IEC) and thyroid hormone binding inhibitor (THBI) were studied in 99 patients with various nonthyroidal illnesses including diabetes mellitus (DM) (n = 35), liver cirrhosis (LC) (n = 33), chronic obstructive pulmonary disease (COPD) (n = 17) and chronic heart failure (CHF) (n = 14). Patients were divided into three groups based on the level of serum T3: Group I (T3 < 50 ng/dl), Group II (50 < or = T3 < 80) and Group III (80 < or = T3). Serum T4, FT3 and the T3/T4 ratio decreased significantly in the order Group III, Group II and Group I (Group III > II > I). The plasma FFA level was 0.91 +/- 0.12 mmol/l in Group I (P < 0.05, vs. Group III), 0.65 +/- 0.06 in Group II and 0.54 +/- 0.04 in Group III, respectively. The incidence of positive IEC was 80.0% in Group I (P < 0.05, vs. Group III), 53.7% in Group II (P < 0.05, vs. Group III) and 34.2% in Group III. However, IEC was not correlated with the serum T3 concentration. The incidence of positive THBI was 80% in Group I (P < 0.05, vs. Group III), 68.3% in Group II and 47.4% in Group III, but THBI was not correlated with the serum T4 level. Positive correlations were observed among FFA, IEC and THBI (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Thyroid function and polyamines. III. Changes in ornithine decarboxylase activity and polyamine contents in the rat thyroid during hyperplasia and involution

Changes in ornithine decarboxylase (ODC) activity and in polyamine contents of the rat thyroid were studied under various experimental conditions. Methylthiouracil (MTU) treatment produced several-fold increases in the thyroid ODC activity and in the content of putrescine, spermidine and spermine within a week. While serum thyrotropin (TSH) levels increased gradually up to 3 weeks, the content of both putrescine and spermidine tended to reach a plateau after 2 weeks of the goitrogen treatment; spermine content continued to increase progressively for 3 weeks. Discontinuance of MTU at 7 days resulted in a rapid decline in the elevated thyroid ODC activity, followed by a diminution of putrescine, spermidine and RNA contents. Thyroidal putrescine, spermidine and RNA responded more sensitively to both introduction and withdrawal of TSH stimulation than thyroidal spermine and DNA. Excess iodide, having no effect on the basal level of thyroid ODC, suppressed the MTU-induced increase in this enzyme activity without affecting circulating TSH, thyroxine (T4) and triiodothyronine (T3) levels. There was a significant negative correlation between the ODC activity and intrathyroidal concentration of iodine in MTU-pretreated rats. Theophylline increased the thyroid weight and ODC activity when given to rats fed with a subeffective dose of MTU. Analyses of serum TSH, T4, T3 and of thyroidal iodine revealed that TSH-induced thyroid ODC activity was suppressed by increased circulating thyroid hormones and/or intrathyroidal iodine. Furthermore, it was suggested that thyroid hormones and excess iodide acted directly on the thyroid to alter polyamine biosynthesis, possibly by changing the responsiveness of the gland to TSH.     

Effect of butyldiiodohydroxybenzoate on pituitary-thyroid interplay.

The effect of BHDB, an analogue of thyroxine, on the pituitary-thyroid system was studied in the rat. BHDB produced low plasma T4 and T3 concentrations similar to those produced by methimazole, but failed to elevate plasma TSH and to produce goiter because of displacement of T4 from the binding protein. Low plasma thyroid hormone concentrations were due to an increase of fecal loss of thyroid hormones. By releasing excess iodide, BHDB blocked the development of goiter produced by methimazole.     

A novel thyroid hormone receptor-beta mutation,not anticipated to occur in resistance to thyroid hormone,causes variable phenotypes

Resistance to thyroid hormones (RTH) is a syndrome characterized by a variable tissue hyposensitivity to thyroid hormones and is linked to mutations in the thyroid hormone receptor-beta (TRbeta) gene. We report here for the first time in vivo the mutation R429W (CCG-->TCG) located in the exon 10. The artificial mutant obtained in vitro displayed a normal T(3)-binding affinity and transactivation function. Therefore, it was thought to produce little, if any, clinical effect and to escape to clinical detection. The present report is at least in part discordant with this prediction since the propositus and his grandmother had an authentic hyperthyroidism with high FT(4) plasma level in the presence of inappropriate TSH. On the other hand, spontaneous variations of clinical features and - interestingly - of plasma FT(4) concentrations with time in the propositus, and the phenotype observed in his mother who never complained with thyrotoxic symptoms, confirmed the in vitro binding and functional predictions. The most intriguing is the clinical course of the grandmother as she first presented with predominant pituitary RTH and a diffuse goiter and finally with a toxic multinodular goiter with normal T(3) and T(4) plasma concentrations and suppressed TSH. In conclusion, we report a novel mutation in the gene encoding the thyroid hormone receptor responsible for predominant pituitary RTH already described in vitro but not in vivo. The fluctuant phenotype of the propositus suggests that other factors modulate the degree of tissue resistance that is under genetic control. Toxic multinodular goiter, possibly due to chronic TSH stimulation during RTH, in addition to the phenotype variability, increases the difficulty to diagnose this thyroid disorder.     

The thyroid reserve in children with chronic lymphocytic thyroiditis revealed by the thyrotropin-releasing hormone and thyroid-stimulating hormone tests

Serum thyroid hormone and TSH concentrations were measured before and after the administration of TRH (10 micrograms/kg body weight) and bovine TSH (10 IU) in 14 children with chronic lymphocytic thyroiditis. The TRH test showed that the responsiveness of TSH was positively correlated with the basal TSH (P less than 0.001) and inversely with the increase in serum thyroid hormones, for delta T3 (P less than 0.05) and for delta T4 (P less than 0.001). Overall, the patients had significantly lower mean values for basal T4, but not for T3. The TSH test revealed that the delta T3 was positively correlated with delta T4 (P less than 0.05). delta T3 after TSH administration was positively correlated with it after TRH (P less than 0.05). The patients were divided into three groups on the basis of their peak TSH values after TRH administration. In Group 1 (peak value below 40 microU/ml; N = 5); T3 increased significantly after TRH and TSH administrations (P less than 0.05 and P less than 0.025, respectively). In addition, delta T4 was significant after TSH administration. In Group 2 (peak TSH above 40 and less than 100 microU/ml; N = 6); only delta T3 after TRH was significant (P less than 0.05). In Group 3 (peak TSH above 100 microU/ml; N = 3); the response of thyroid hormones was blunted. Thus, the thyroid hormone responses to endogenous TSH coincided with that to exogenous TSH, and the exaggerated TSH response to TRH indicates decreased thyroid reserve.     

Hormone profile of hypothyroidism in an area of the Central African Republic with endemic goiter]

In the Ouham region of Centro African Republic, one of the present Authors (B.P.) described a severe goiter endemia due to marked iodine deficiency and high daily intake of manioc as staple food. In the present study serum TSH, T3 and T4 of 233 subjects were determined; 150 of them lived in rural villages (Group 1) and 83 lived in Bocaranga, chief town of the province (Group 2). The blood samples done contemporaneously to the epidemiological survey, were strictly randomized in the population examined. The subjects of each group were divided in 4 sub-groups: A) with TSH, T3 and T4 in normal range; B) with elevated TSH; C) with elevated TSH and sub-normal T4; D) with elevated TSH and sub-normal T3 and T4. An apparently euthyroid pattern of TSH, T3 and T4 was evident in only 60 subjects (19.3% from group 1; 37.35% from group 2); the remaining 173 (80.67% from group 1; 62.65% from group 2) were hypothyroid (subclinical in the sub-group B; mild in the sub-group C; overt in the sub-group D). The mean hormonal values of the apparently euthyroid subjects (sub-group A) in the villages and in the chief town, were significantly different (p less than 0.05) from the control values of our laboratory. More significant differences were clearly evident between the control values and the mean values of sub-groups B, C and D in each of the two groups (1 villages; 2 chief town).(ABSTRACT TRUNCATED AT 250 WORDS)     

Concomitant association of thyroid sarcoidosis and Graves' disease

OBJECTIVE: Graves' disease (GD) with sarcoid involvement of the thyroid gland has rarely been reported. METHOD: We report a case of GD with thyroid sarcoidosis in a 28-year-old woman. Thyroid function was assessed by triiodothyronine (T(3)), thyroxine (T(4)), thyroid-stimulating hormone (TSH) and TSH receptor antibodies (TSH-R Ab). Thyroid scintigraphy, ultrasound and fine-needle aspiration biopsy were performed. The patient underwent surgery. RESULT: The patient had a nodular goiter. Serum T(3), T(4) and TSH-R Ab levels were elevated with suppressed TSH level. Scintigraphy showed diffuse activity as seen in GD, and ultrasound revealed that parenchyma was heterogenous. Sarcoidosis was discovered on routine chest X-ray. Although no sarcoid involvement was found on specimen, the thyroid gland showed non-caseating granulomas on histology. CONCLUSION: Since sarcoid involvement of the thyroid gland can cause hypofunction, we report the uncommon infiltration of sarcoidosis with hyperthyroidism.     

Effects of dietary caloric restriction and aging on thyroid hormones of rhesus monkeys.

Plasma levels of thyroid hormones - triiodothyronine (T 3 ), thyroxin (T 4 ), and thyroid-stimulating hormone (TSH) were measured in male and female rhesus monkeys (Macaca mulatta) fed either ad libitum or a 30 % calorie-restricted (CR) diet (males for 11 years; females for 6 years). The same hormones were measured in another group of young male rhesus monkeys during adaptation to the 30 % CR regimen. Both long- and shorter-term CR diet lowered total T 3 in plasma of the monkeys. The effect appeared to be greater in younger monkeys than in older counterparts. No effects of CR diet were detected for either free or total T 4, although unlike T 3, levels of this hormone decreased with age. TSH levels also decreased with age, and were increased by long-term CR diet in older monkeys only. No consistent effects of shorter-term CR diet were observed for TSH. In the light of the effects of the thyroid axis on overall metabolism, these results suggest a possible mechanism by which CR diets may elicit their well-known beneficial 'anti-aging' effects in mammals.