Diagnostic value of thyrotropin releasing hormone test in 129 patients with suspected tumoral hyperprolactinemia.

In 129 hyperprolactinemic (PRL > or = 100 ng/mL) and 100 normoprolactinemic patients (PRL 0-25 ng/mL), delta max. PRL (the difference between maximal prolactin (PRL) after thyrotropin releasing hormone (TRH) injection and basal value) was compared with basal PRL and computed tomography (CT) of the sellar region. In 122 hyperprolactinemic patients delta max. PRL was < 100%, while tumor was found in 106 of them. In the remainder seven hyperprolactinemic patients delta max. PRL was > or = 100% and CT showed no tumor. A significant difference in delta max. PRL between hyperprolactinemic patients without and those with verified adenoma was found and showed a significant negative correlation with basal PRL. Between 122 hyperprolactinemic patients with delta max. PRL < 100%, mean basal PRL and duration of clinical symptoms were significantly lower in 16 patients with normal CT compared to 106 patients with tumor. All normoprolactinemic patients showed delta max. PRL > or = 100% and no tumor on CT. PRL stimulation disturbance precedes tumor visualization and represents a decisive diagnostic parameter in hyperprolactinemic patients with no tumor signs.

Lymphocytic adenohypophysitis simulating a pituitary adenoma in a pregnant woman.

The lymphocytic hypophysitis, appearing in women during the third trimester of pregnancy or early post-partum period, is a rare cause of hypopituitarism and pituitary enlargement. A 39 year-old woman presented in the 37th week of pregnancy with bilateral heteronymous quadrantanopsia, CT indicative of tumorous mass and symptoms of hypopituitarism with decreased thyroid hormone and thyrotrophin levels, and low normal level of cortisol. After the birth of a healthy male child the patient breastfed for 10 days, sight disturbances disappeared, but amenorrhea persisted. Upon admittance the visual field showed no abnormalities. MR of the sellar region confirmed previous CT findings. Endocrinological testing confirmed secondary hypothyroidism and cortisol deficiency, normal levels of prolactin with satisfactory reaction to thyroliberin. Histology showed mononuclear infiltration, and immunohistochemistry revealed T-cells (CD3) at the borders, and B-cells (CD20) in the follicular center. Due to enlargement of the pituitary associated with hypopituitarism, an incorrect diagnosis of a tumor could be made.

The effects of cortisol, 11-epicortisol, and lysine vasopressin on DNA and RNA synthesis in isolated human adrenocorticotropic hormone-secreting pituitary tumor cells.

The effects of cortisol, its steric analog 11-epicortisol, and lysine vasopressin (LVP) on DNA and RNA synthesis in isolated adrenocorticotropic hormone-secreting human pituitary tumor cells obtained by transsphenoidal surgery were studied using [3H]thymidine incorporation in DNA and [3H]uridine in RNA. Cortisol suppressed RNA and, to a greater extent, DNA synthesis in these cells. This could explain the slow growth of pituitary tumors in patients with Cushing's disease and the rapid growth of Nelson's pituitary tumors after bilateral adrenalectomy. 11-Epicortisol also suppressed RNA synthesis, but it had a stimulatory effect on DNA synthesis, which indicates a high specificity of glucocorticoid receptors. When applied together with cortisol, 11-epicortisol antagonized the suppressive effects of cortisol on DNA synthesis. Although LVP stimulated RNA synthesis, it suppressed DNA synthesis in most of the tumor cells.

Thyroid hormone economy in response to extreme cold exposure in healthy factory workers.

The effects of cold exposure on serum total T4 (TT4), total T3 (TT3), free T4 (FT4), free T3 (FT3), rT3, TSH, T4-binding globulin (TBG), and T3 resin uptake were investigated in 82 euthyroid factory workers. Twenty-five workers (group 1) were exposed intermittently (approximately 3.5 h daily) to extreme cold (-40 to -20 C) during the 8-h work shift, and 47 (group 2) were exposed to moderate cold (-10 to 8 C) for the entire 8 h. Ten individuals working at room temperature for the same period also were studied. After cold exposure, serum TT4 decreased in group 1 and did not change in group 2, whereas FT4 did not change in group 1 and increased in group 2. After exposure, serum TT3 and rT3 decreased significantly in both groups, while FT3 did not change in either. The basal serum TT4 levels in groups 1 and 2 were significantly lower than those in the control group, whereas those of FT4 and FT3 were higher. Thus, cold exposure had opposite effects on total thyroid hormones and their free fractions, consistent with a cold-induced decrease in thyroid hormone-binding capacity. A postexposure decrease in serum TBG was found in women in group 2, but not in men in either group 2 or group 1, suggesting that factors other than decreased TBG are also involved. The results suggest the possibilities that 1) decreased thyroid hormone-binding capacity is an adaptive response to cold exposure, and/or 2) increased free thyroid hormone levels in response to cold exposure result in a new higher equilibrium between extracellular and intracellular FT4 and FT3.

Daily iodine intake in healthy children and adults and in goitrous patients in nonendemic Yugoslav area.

Daily iodine intake has been investigated in 52 healthy children (5-14 years), 112 healthy adults and in 39 patients with nontoxic goiter from the area of Zagreb/Yugoslavia. Fourteen goitrous patients received 1-thyroxine 150 micrograms daily for at least three months before the examination. Iodine intake has been estimated on the basis of urinary iodine excretion (microgram I-/g creatinine) in the first morning specimen. Iodine excretion in nontreated goitrous patients (92 +/- 30; Mean +/- SD) was significantly lower than in healthy adults (112 +/- 38), while the value in treated goitrous patients (165 +/- 69) was significantly higher than that in nontreated goitrous and healthy adult subjects. The results suggest that Zagreb area, although classified as nonendemic, has borderline iodine intake, and that relative iodine deficiency is of importance in goiter formation. The authors plead for increased daily iodine intake through increased table salt iodisation from actual amount of 10 to 20 to 25 mg KI/kg salt in order to provide an average daily intake of 250 micrograms of iodine.

Similar concentrations of thyroidal iodothyronines and T3/T4 ratio in normal thyroids from two Yugoslav districts with different iodine intake.

In spite of different daily iodine intake in two yugoslav districts (littoral-Split 297 +/- 76 (Mean +/- SD) and continental-Zagreb 111 +/- 36 micrograms/g creatinine, p less than 0.001), thyroidal iodothyronine concentrations and T4/T3 ratio in normal post mortem thyroids were comparable. T4 was 260.0 +/- 42.6 micrograms/g w.w. (Mean +/- SE) in Split group vrs. 279.9 +/- 59.4 in Zagreb. T3 was 12.8-2.0 vrs. 12.8 +/- 2.2 and T4/T3 ratio 21.6 +/- 1.9 vrs. 21.1 +/- 2.9 in Split and Zagreb, respectively. It has been concluded that relatively small difference in iodine intake has no effect on thyroidal concentrations of iodothyronines and T4/T3 ratio.

The urinary iodide excretion in subjects on different diets.

The urinary iodide excretion in hospital subjects on regular and different restrictive diets was investigated. In subjects on a regular diet the average urinary iodide (microgram I-/g creatinine; mean +/- SD) was 104.7 +/- 36.7. In subjects on a low caloric diet the urinary iodide content was 101.1 +/- 24.2; in subjects starving for weight-reduction the mean value was 63.2 +/- 23.9, significantly different from the controls (p less than 0.005). In subjects on a high-caloric diet the urinary iodide was 145 +/- 45.4, in those on a hepatoprotective diet 96.8 +/- 18.8, respectively. The iodide excretion in subjects on an ulcer-protective diet was on the average 76.4 +/- 22.3 which was significantly different from those on a regular diet (p less than 0.01).

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.

Thyroidal thyroxine and triiodothyronine in autonomously functioning thyroid nodule and paranodular tissue.

Thyroidal thyroxine (T4), triiodothyronine (T3), thyroglobulin (Tg) and T4/T3 ratio were investigated in nodular and paranodular tissue from 16 patients with autonomously functioning thyroid adenomas. The concentration of T4 and T3 in the nodule were 97.7 +/- 20.5 (Mean +/- SE) and 10.2 +/- 2.4 micrograms/g wet weight (w.w.). Both iodothyronines were significantly lower in paranodular tissue (22.6 +/- 4.8 and 1.45 +/- 0.32 micrograms/g w.w., respectively), but with disproportionately decreased T3 which resulted in T4/T3 ratio (25.4 +/- 6.4) higher than in adenoma tissue (11.2 +/- 1.6). In patients with high normal or supranormal serum T3 concentration, thyroidal concentration of T3 in adenoma tissue was higher (15.6 +/- 5.0 vs. 6.3 +/- 1.2 micrograms/g w.w.) and T4/T3 ratio lower (8.05 +/- 2.1 vs. 13.2 +/- 1.9) than in patients with normal serum T3. The results suggest that thyroid release of T3 from adenoma is relatively higher than T4 in patients with autonomously functioning thyroid nodules and increased peripheral T3.

Low thyroidal T3 in nodular goitrous tissue.

Six nodular tissues of non-treated and four of treated patients (suppressive treatment with thyroid hormones from three months to two years until the operation) with nodular non-toxic goitre contained low T3 (less than 1 ug/g w.w.). The results of iodothyronines and thyroglobulin (Tg) were compared with respective tissues containing T3 greater than 1 ug/g w.w. In non-treated patients, nodular tissues with low T3 and very high T4/T3 ratio showed T4 and Tg concentrations not different from the tissues with T3 greater than 1 ug/g w.w. In the goitres with low T3 of treated patients, T4 was also reduced but disproportionately to T3. Microscopically, nodular goitres with low T3 were characterized with gross fibrous infiltration and diffuse haemorrhage which was substantially different from histological findings in nodular goitres with T3 greater than 1 ug/g w.w. High T4/T3 ratio in the tissues with low T3 is similar to increased T4/T3 ratio in paranodular tissues of autonomously functioning adenomas. The results suggest that low T3 and high T4/T3 ratio in nodular goitrous tissue could be due to grossly impaired thyroid function or due to suppressed secretion of TSH.

[Computed tomography of the sella turcica contents in the transverse and frontal planes]. / Computertomographie des Inhaltes der Sella turcica in transversaler und frontaler Ebene.

Computed tomography of the pituitary fossa in the axial and coronal plane have been performed in 40 patients. The use of both planes has improved diagnostic accuracy through a more exact spatial demonstration. The method has also been reliable in the detection of pituitary microadenomas. The use of both planes has a limited diagnostic accuracy due artefacts in coronal plane.