Immunoreactive somatostatin in rat hypophysial portal blood.

Somatostatin levels have been determined by RIA in hypophysial portal blood of pentobarbital-anesthetized male rats. In most animals, immunoreactive somatostatin (SRIF) levels were higher in hypophysial portal blood than in systemic blood. In euthyroid rats, the mean level was 158 +/- 27 pg/ml (n = 8); SRIF was undetectable (less than 30 pg/ml) in systemic blood of these rats. It is suggested that endogenous SRIF was not degraded during the collection of stalk blood, since synthetic SRIF is stable when incubated in rat serum during 4 min at 37 c and 2 h at 0 C, i.e. under the conditions the blood was kept during the collection. SRIF in hypophysial portal plasma had the same immunoreactivity with a specific antiserum against SRIF as did synthetic SRIF. Gel filtration of hypophysial portal plasma revealed two immunoreactive peaks, the major one corresponding to synthetic SRIF, the smaller one representing a larger molecular form. Thyroidectomy and excess of T4 did not modify the levels of SRIF in hypophysial portal blood, suggestinc SRIF is stable when incubated in rat serum during 4 min at 37 C and 2 h at 0 C, i.e. under the conditions the blood was kept during the collection. SRIF in hypophysial portal plasma had the same immunoreactivity with a specific antiserum against SRIF as did synthetic SRIF. Gel filtration of hypophysial portal plasma revealed two immunoreactive peaks, the major one corresponding to synthetic SRIF, the smaller one representing a large molecular form. Thyroidectomy and excess of T4 did not modify the levels of SRIF in hypophysial portal blood, suggesting that the feedback of thyroid hormones on TSH secretion does not involve changes in the secretion of SRIF by the hypothalamus.

Lasting remissions in patients treated for Graves' hyperthyroidism with propranolol alone: a pattern of spontaneous evolution of the disease.

Twenty-six patients with Graves' hyperthyroidism treated only with propranolol for 1-21 months have been followed up to 5 years. The patients were evaluated before treatment, at 15, 30, and 90 days during treatment, and then at 90-day intervals during propranolol treatment by clinical examination and measurement of serum free T3, free T4, rT3, TSH, and sex hormone-binding globulin concentrations and serum anti-thyroglobulin, antithyroid microsomal, antithyroid peroxidase, and thyroid-stimulating autoantibodies. Eighteen patients who had no biochemical improvement during propranolol therapy or relapsed after initial improvement were treated conventionally. In contrast, eight patients had a biochemical remission, which has lasted 30-48 months after propranolol withdrawal. The biochemical values before and during treatment did not differ among the two groups of patients, except for the initial serum free T3 levels which were significantly higher in the patients who had no remission. Serum TSH levels returned to normal only in patients who had a long-lasting remission. While thyroid autoantibodies decreased or disappeared during follow-up, the evolution of thyroid-stimulating autoantibody values was grossly related to the clinical outcome. Long-lasting remissions may occur in patients with hyperthyroidism due to Graves' disease not given ablative or antithyroid drug therapy. Since propranolol is devoid of antithyroid and immunosuppressive actions, these remissions are probably spontaneous. Although they tended to occur in patients with less severe disease, no biological parameter was found that predicted the outcome.

Vitamin B1, B2, B6, and C status in hospital inpatients.

The status of vitamin B1, B2, B6 and C was investigated in 656 hospital inpatients by means of a dietary interview, biochemical studies, and clinical investigation. The daily intake was lower than the Recommended Dietary Allowance for vitamin B1 in 57%, B2 in 47%, B6 in 53%, and C in 9% of the patients; it was less than half the Recommended Dietary Allowance in 19, 12, 15, and 3%, respectively. A biochemical deficiency was observed in 25% of the patients for vitamin B1, in 11% for B2, in 25% for B6, and in 14% for C. On the basis of the parameters selected for this study, the biochemical vitamin status, the dietary vitamin intake, and the clinical symptoms correlated significantly with each other except in the case of vitamin B6.

Increased monoester lipase activity in red blood cells during hyperthyroidism.

Human red blood cells (RBC) contain a monoester lipase (MEL) activity which is tightly associated with the cell membrane and has its active site externally oriented, as inferred from the ability of the intact cell to hydrolyse an exogenously added lipid substrate. Membrane-bound MEL activity was measured by a radiochemical assay in intact RBC from 29 untreated hyperthyroid patients. The mean (+/- S.D.) MEL level was higher (P less than 0.01) in these patients (1220 +/- 212 mu./10(12) RBC) than in the control group (1010 +/- 120 mu./10(12) RBC). There was no difference between men and women. The increase in MEL values was associated with significantly (P less than 0.001) decreased values of mean cellular volume and mean cellular haemoglobin content. A continued study of 13 patients, who became euthyroid with treatment, showed a normalization of the MEL values in RBC. The increased lipolytic potency of RBC represents a new characteristic of hyperthyroid patients. Further exploration of the possible diagnostic or prognostic implications of this enzymatic change seems warranted.

Prevalence of autoantibodies to thyroperoxidase in patients with various thyroid and autoimmune diseases.

An original radioimmunoassay for quantitation of circulating autoantibodies (aAb) to thyroperoxidase (TPO) proved to be well suited for large scale routine testing. The present study was aimed to assess the prevalence of aAb to TPO in patients with various thyroid and autoimmune disease and, for comparison, in women referred for reproductive disorders and indication of in vitro fertilization. Anti-TPO aAb were measured in sera from 32 healthy subjects and 262 patients thoroughly investigated for thyroid dysfunction. As determined in healthy subjects, the normal level of aAb to TPO in serum ranged from 0.30 to 3.07 mg/l (of affinity-purified) anti-TPO aAb. Anti-TPO and anti-MIC aAb levels were both normal in 115 patients and correlated well (r = 0.835, P less than 0.001) in the remaining 147 patients. Coexistence of normal level of anti-TPO aAb and abnormal level of anti-MIC aAb was found in 4 patients and ascribed to a lack of specificity or sensitivity of the test for anti-MIC aAb. Coexistence of abnormal level of anti-TPO aAb and normal level of anti-MIC aAb was found in 67 patients of whom 62 presented only slightly elevated (3.1 to 10.0 mg/l) anti-TPO aAb concentration; the 5 remaining patients, all with overt thyroid autoimmune disease, showed anti-TPO levels between 10.7 to 100.7 mg/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of 41-CRF antiserum on the secretion of ACTH, B-endorphin and alpha-MSH in the rat.

In order to elucidate the physiological role of the 41 amino-acid residue corticotropin-releasing factor (41-CRF) on the secretion of ACTH, B-Endorphin and alpha-MSH, plasma levels of these peptides were measured by radioimmunoassay in intact and adrenalectomized rats, two hours after the injection of either 41-CRF antiserum (CRF-AS) or normal rabbit serum for controls. The administration of CRF-AS strikingly lowered the plasma ACTH levels in both intact and adrenalectomized rats. A statistically significant reduction of plasma levels of B-Endorphin was also observed in the same rats. However, the effect of CRF-AS on B-Endorphin release was less pronounced than the effect on ACTH release. No changes in plasma alpha-MSH levels were observed after passive immunization with CRF-AS. We conclude that, in the rat, 41-CRF plays a physiological role in the regulation of ACTH and B-Endorphin secretion, but is not involved in the regulation of alpha-MSH release from the pituitary gland.

[Determination of plasma catecholamine. Effects of glucagon administration]. / Dosage des catécholamines plasmatiques. Effets de l'administration de glucagon.

Basal plasma dopamine (DA), Norépinephrine (NE) and Epinephrine (E) were determined in controls (n = 15) essential hypertension (n = 19) and Pheochromocytoma (n = 9). Plasma NE was significantly higher in essential hypertension than in control and in 5 cases, plasma NE or E was 3 SD above mean control values. In 8/9 pheochromocytomas DA, E or NE were significantly elevated. In 1 case, catecholamine levels were within normal range during normotensive period. When a provocative glucagon test (1 mg I.V) was performed in controls, there was no change in blood pressure DA and NE levels, but a significant increase in plasma E 2.5 and 5 min. after injection. Similar results were obtained in 8/10 cases of labile hypertension. However in 2 cases plasma NE or E increased significantly without elevation in blood pressure. In 3/4 pheochromocytomas under normotensive phase, blood pressure and plasma catecholamines increased significantly; however in 1 case, no change was observed.

[Hypophyseal-Leydig function in the diabetic]. / Fonction hypophyso-leydigienne du diabétique.

Experimental diabetes in animals induces marked alterations of gonadal androgenic functions: reduction in testis weight, morphological alterations of Leydig cells, decrease of plasma testosterone levels and reduction of the ability of the Leydig cells to secrete testosterone in vitro. hCG treatment restores the testicular endocrine function; in addition several morphological and functional changes are observed in the hypothalamic-hypophyseal-gonadal axis which are probably responsible for the testicular lesions found in untreated experimental diabetes mellitus. In diabetic men, the hypothalamic-hypophyseal-gonadal axis seems to be normal (with exception of individual cases); Mean plasma levels of testosterone, LH, FSH and the responses of the gonadal axis to hCG and LHRH are normal.

[Discordance of total plasma l-triiodothyronine and l-thyroxine in thyroid diseases]. / Discordance des taux plasmatiques de l-triiodothyronine et de l-thyroxine totales dans les maladies thyroïdiennes.

Radioimmunoassay (RIA) for plasma T3 has been proposed in the diagnosis of thyroid disease. 1 171 simultaneous determination (RIA) of plasma Thyrotropin-Stimulating Hormone (TSH), triiodothyronine (T3) and thyroxine (T4) have been performed in unselected patients under suspicion of a thyroid disease. 81.8% of the cases showed a good agreement between T3 and T4 levels. The remaining 18.2% can be divided into 6 groups: 1. High T3-normal T4 : 51% of the discrepancies: Graves disease untreated (16%) or treated (4%); sporadic goiter (13%); growth failure (8%); hypothyroidism under treatment (6%); thyroiditis, Graves ophtalmopathy, toxic adenoma (4%); 2. High T3-low T4 : 6.5%; sporadic goiter (3%); hypothyroidism (3%); 3. Normal T3-low T4 : 22%: Graves disease under treatment (6%); sporadic goiter (4.5%); subacute thyroiditis (3%); hypothyroidism (3%); miscellaneous (5.5%); 4. Normal T3-High T4 : 9.5%; thyroidectomized patients for cancer well-substituted with T4 (6%); miscellaneous (3.5%) including 1 case of Graves disease; 5. Low T3-normal T4 : 8% 8%: sporadic goiter (4%); hypothyroidism (2%); treated hyperthyroidism (2%); 6. Low T3-high T4 : 3% : including 1 case of hyperthyroidism and 2 cases of thyroidectomized patients well-substituted with T4. In conclusion discrepancies between T3 and T4 levels have been observed mainly in untreated or treated Graves disease (high T3-normal or low T4) and in hypothyroidism (normal or high T3-low T4). The basal TSH and TSH peak after I.V. injection of TRH (65 cases) are in better agreement with T4 level than with T3 level. Indeed, both TRS values are high when T4 is low while T3 is normal of high.

[Hypoparathyroidism in adults (author's transl)]. / L'insuffisance parathyroïdienne de l'adulte.

The authors studied the clinical characteristics of primary and post-operative hypoparathyroidism in 39 patients. Laboratory follow-up data were compared under two different treatment programs using either AT 10 or 25 Hydroxycholecalciferol (25 OHCC). Clinical analysis revealed the atypical characteristics of primary hypoparathyroidism. From a therapeutic standpoint, AT 10 and 25 OHCC were equally effective in provoking a return to normal plasma calcium levels, except in complex cases of vitamin D resistance. 25 OHCC proved much easier to manipulate than at 10 and offered a higher security with respect tothe risk of hypercalcemia. The biological activity of 25 OHCC seems to differ from that of AT 10, especially regarding phosphorus metabolism.

[Immunoreactive somatostatin in rat hypophysial portal blood (author's transl)]. / Concentration de somatostatine dans le sang porte hypophysaire du rat.

Somatostatin levels have been determined by radioimmunoassay in hypophysial portal blood of pentobarbital-anesthetized male rats. In euthyroid rats, the mean level was 158 +/- 27 pg/ml (n = 8); somatostatin was undetectable (less than 30 pg/ml) in systemic blood of these rats. Thyroidectomy and excess of T4 did not modify the levels of somatostatin in hypophysial portal blood.

[Plasma DHA, DHAS and cortisol levels after injection of beta 1-24 corticotrophin beta 1-24 ACTH in normal adult women (author's transl)]. / Modifications de concentrations de déhydroepiandrostérone, déhydroepiandrostérone sulfate et cortisol dans le plasma de la femme adulte normale après stimulation par la corticotrophine.

Plasma DHA, DHAS and cortisol levels were measured by R.I.A. before and after intravenous and intramuscular injection of beta 1-24 ACTH. In 7 normal adult women, plasma cortisol and DHA levels rose sharply in response to beta 1-24 ACTH (0,25 mg) i. v injection; in opposition, plasma DHAS levels did not change significantly 30 and 120 minutes after the injection. In 9 normal adults women, the i. m injection of Zn beta 1-24 ACTH (1 mg) caused a significant increase in both plasma cortisol, DHA and DHAS levels 8 and 24 hours after the injection.

[Adrenal tumors of fortuitous discovery. 13 cases]. / Tumeurs surrénaliennes de découverte fortuite. Treize observations.

An adrenal mass without any clinical or biological symptom was accidentally discovered in thirteen patients. All patients underwent surgical exploration. After surgery, pathological studies showed lesions of corticosuprarenaloma (5 considered benign, 1 malignant and 1 uncertain) myelolipoma (2 cases), adrenal cyst, ganglioneuroma, haemangioma and lymphangioma (1 case each). Since no reliable preoperative investigations are yet available to assess the nature of adrenal masses, and since these may be due to benign or malignant endocrine tumours, their surgical removal is indicated.

[Bone density after iatrogenic subclinical long-term thyrotoxicosis. Measurement by dual photon absorptiometry]. / Densité osseuse après thyrotoxicose iatrogène infraclinique au long cours. Mesure par absorptiométrie biphotonique.

Thyrotoxicosis may be held responsible for osteoporosis. The question is whether a very slight subclinical hyperthyroidism, as is desirable in the post-operative treatment of differentiated thyroid carcinoma, can in the long run be detrimental to bone tissue. In a series of 37 patients, aged 50.9 +/- 11.1 years, presenting with the features of subclinical hyperthyroidism of 8.0 +/- 4.8 years duration, the authors have been unable to find any change in paraclinical parameters of bone and calcium-phosphate metabolism. Thirty-six of these 37 patients showed no abnormal decrease of vertebral bone density measured by dual photon absorptiometry.