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Biomedical subjects

J Golstein

Publications and source records attributed to J Golstein.

At least 55 records · Page 3Linked to original sources
PubMed1983

Measurement of thyroxine conversion to triiodothyronine using human lymphocytes. A useful and simple laboratory technique.

The deiodination of T4 to T3 has been studied after incubation of whole lymphocytes with different T4 concentrations, followed by a T3 radioimmunological determination performed on unextracted samples. The lymphocytes were isolated from blood from normal volunteers of both sexes and different age classes as well as from myxedematous subjects and patients with low T3 syndrome. The T3 production, in normal subjects, expressed as pmol/10.10(6) cells was 0.41 +/- 0.75 (T4 = 4.10(-7) M, n = 12), 1.43 +/- 0.14 (T4 = 4.10(-6) M, n = 26) and 1.65 +/- 0.29 (T4 = 8.10(-6) M, n = 11). There was no sex or age-related difference. In 3 myxedematous patients the T3 production was lower than the corresponding value obtained in normal subjects. The T3 production in patients with low T3 syndrome was lower than in controls (p less than 0.001); an inverse correlation was found between the T3 production and the serum rT3 levels, whereas no correlation could be found with serum T3 levels.

Adult↗
PubMed1983

Effects of "jet lag" on hormonal patterns. IV. Time shifts increase growth hormone release.

Twenty-four-hour GH profiles were obtained in five normal male volunteers before travel, 1, 11, and 21 days after the Brussels-Chicago flight (time shift, 7 h); and 1, 11, and 21 days after the return flight. The westward and eastward travels involved, respectively, periods of 23 and 33 h of sleep deprivation. One year later, two of the five volunteers were submitted, in the laboratory, to an investigation mimicking the conditions of sleep deprivation undergone in the course of the eastward travel and involving two 24-h periods of blood sampling. Blood samples were drawn every 15 min, and sleep was polygraphically monitored. The amounts of GH secreted were quantified, and their relationship with the different sleep stages was analyzed. Time shifts, whether caused by "jet lag" or by sleep deprivation in the laboratory, had two effects on GH secretory patterns. First, a marked increase in GH release, due to an augmentation of the magnitude, rather than the number, of secretory spikes was observed, independently of sleep disturbances. Return to basal levels was slower after westward than after eastward travel and took at least 11 days. Second, 1 day after the eastward transportation as well as immediately after 33 h of sleep deprivation, the major GH spike, which occurred in early sleep in the other studies, was shifted to late sleep. In these investigations, the only consistent alteration of sleep was a reduction in the amount of rapid eye movement (REM) stage. The occurrence of GH spikes in sleep was significantly associated with slow wave (SW) stage. However, total amounts of GH secreted during sleep were negatively correlated with the total duration of REM stages rather than positively correlated with the total duration of SW stages. A spike by spike analysis showed that the amount of GH secreted correlates best with the ratio (SW - REM) to (SW + REM), which relates the amount of REM preceding the spike to the amount of SW during the spike and thus constitutes an indicator of the status of the REM-non-REM oscillation.

Adaptation, Physiological↗
PubMed1981

Effect of aging on the morphology and function of the thyroid gland of the cream hamster. Further evidence for two different mechanisms of hormone secretion.

The effect of aging on the morphology and function of the thyroid gland of the cream hamster was studied by light and electron microscopy coupled with autoradiography or histochemistry. Morphologically, aging induces an accumulation of lysosomal dense bodies and a loss of the phagocytosis of colloid droplets after stimulation with TSH. Iodine uptake and organification occur normally and thyroglobulin synthesis, estimated by autoradiography with 3H-leucine, is not different from that observed in young animals. The basal T4 and T3 plasma levels are lower in the old animals. A low iodine diet administered for several months prevents the age related accumulation of lysosomal dense bodies. Hormone secretion seems to proceed by two different mechanisms; phagocytosis of colloid droplets, the classical mechanism that decreases with age, and an additional mechanism, probably micropinocytosis, that is maintained during the whole lifespan.

Aging↗
PubMed1979

Effect of cyproheptadine on thyrotrophin and prolactin secretion in normal man.

In order to investigate the effect of cyproheptadine, a compound with antiserotoninergic activity, on the secretion of thyrotrophin (TSH) and prolactin (PRL), the nocturnal secretory patterns of these hormones have been studied in 4 normal men in the basal state and after an oral treatment with the drug. In addition, the TSH and PRL responses to TRH of 6 women were compared in the basal conditions and after cyproheptadine treatment. The TSH nocturnal secretion was slightly modified by drug treatment. The response to TRH as well as the basal levels were comparable in the treated and non-treated subjects. In contrast, the PRL secretion measured through the nocturnal investigation was significantly inhibited by cyproheptadine administration as were the PRL basal levels in the TRH test. The PRL response to TRH was comparable in both situations.

Adult↗
PubMed1978

Pituitary-thyroid axis during short term, mild and severe, iodine depletion in the rat.

To investigate the most early events occurring during the adaptation of the pituitary-thyroid axis to iodine depletion, two rat populations were submitted to 4 week low iodine regimens of different severity. The variations of the following parameters were studied: pituitary thyrotropin (TSH) concentration, serum thyroxine (T4), triiodothyronine (T3) and TSH, thyroid weight and thyroid iodine concentration. In the first population, mildly iodine depleted, serum and pituitary TSH remained unchanged. The weight of the thyroid increased by the 12th day. Serum T4 dropped by the 26th day. Serum T3 tended to increase during the whole observation period. In the second population, more severely iodine depleted, the increase in thyroid weight appeared by the 4th day. Serum T3 increased from day 13 to day 20, then returned to normal. Serum TSH increased and serum T4 decreased by the 20th day. These results suggest that, in the adaptation to iodine deficiency in the rat, autonomous thyroid regulatory mechanisms play a major role at the onset of goiter growth. On the other hand, most likely a combined effect of serum T3 and T4 triggers variations in pituitary TSH secretion.

Animals↗
PubMed1978

A low T3 syndrome in diabetic ketoacidosis.

The pituitary-thyroid axis was investigated in nineteen euthyroid patients with severe diabetic ketoacidosis. A 'low T3 syndrome' was found, with the following characteristics: lowered serum concentrations of triiodothyronine (T3), increased reverse triiodothyronine (rT3), slightly low thyroxine (T4), normal thyrotrophin (TSH), slightly increased triiodothyronine uptake (RT3U) values, and a blunted TSH response to thyrotrophin-releasing hormone (TRH). These disturbances in thyroid-function tests required several days good control of the diabetes to be corrected, at least partially. The data suggest the presence of an abnormal extrathyroidal T4 metabolism as well as a pituitary defect. Caution is recommended in the interpretation of thyroid-function tests during and several days after the treatment of diabetic ketoacidosis.

Adult↗
PubMed1978

Acute endocrine profile of sulpiride in the human.

Normal men and normally menstruating women received i.m. injections of 0.1 to 4.0 mg/kg sulpiride. This psychotropic drug induced a very rapid (already significant after 5 minutes) and sustained (still significant after 7 hours) elevation of prolactin (PRL) concentrations in all subjects with no consistent modification of LH and FSH. After injection of 4.0 mg/kg, there was similarly no modification of mean TSH concentrations in the women tested in the luteal phase, as well as of mean GH levels in men. Sulpiride prevented the inhibitory effect on PRL levels of 500 mg levodopa, administered orally simultaneously; levodopa administered 2 hours prior to sulpiride failed to counteract the PRL-stimulatory effect of sulpiride. Under chronic sulpiride-induced hyperprolactinaemia, levodopa exhibited however a very slight inhibitory effect on PRL concentrations. These data are in agreement with the hypothesis that sulpiride acts mainly at the pituitary level by blocking dopamine receptors of the lactotropes and support the concept that the menstrual cycle perturbations observed under chronic sulpiride administration result from hyperprolactinaemia itself or from a mechanism quite similar to that by which sulpiride induces hyperprolactinaemia.

Adolescent↗
PubMed1978

Thyrotrophin, prolactin and growth hormone responses to TRH in barbiturate coma and in depression.

The effects of 200 microgram thyrotrophin-releasing hormone (TRH) i.v. on thyrotrophin (TSH), prolactin (PRL), growth hormone (GH) and triiodothyronine (T3) were studied in eight patients with barbiturate coma due to attempted suicide, in the same patients after recovery, in eight depressive patients and in eight normal controls. The patients with barbiturate coma presented normal basal TSH and PRL, elevated basal GH and normal PRL but blunted TSH responses to TRH; their GH concentrations varied widely without consistent relation to TRH administration. The same patients after recovery from coma presented normal TSH and PRL, slightly elevated basal GH, and normal PRL but blunted TSH responses to TRH; in four of these patients, a clear-cut rise in GH (i.e. more than 10 ng/ml) occurred after TRH administration. The depressive patients presented normal basal TSH and PRL, slightly elevated basal GH, and normal PRL but blunted TSH responses to TRH; in four of these patients, a moderated rise in GH (less than 10 ng/ml) occurred after TRH administration. The increment in T3 concentrations 120 min after TRH was found reduced in the comatose patients only. Basal cortisol was measured in all the subjects and found elevated in the comatose patients only. It is concluded that the abnormal TSH and GH responses to TRH observed in patients with barbiturate coma are more likely related to depressive illness than to an effect of barbiturates at the pituitary level. Barbiturates might affect thyroid secretion.

Adolescent↗
PubMed1977

[The sella turcica and pituitary function in congenital hypothyroidism due to thyroid ectopia or hypogenesis (author's transl)].

Nine patients suffering from hypothyroidism due to thyroid ectopia or hypogenesis, with a large sella turcica, were examined at adolescence or during adult life. TSH, prolactin and growth hormone function were studied. Basal plasma TSH, evaluated in 5 cases, was raised and responded explosively to stimulation with TRH. The administration of L-dopa was not associated with any notable changes in TSH. In one case, the chronic administration of l-T3 resulted in a fall followed by normalisation in plasma TSH levels. Basal plasma prolactin, explored in 6 patients, was high in 4 females and normal in 2 males. TRH stimulation resulted in a marked increased in prolactin in the female cases and a moderate increase in the male cases. L-dopa caused a fall only in high prolactin values. Stimulation of GH by argininehydrochloride, insulin hypoglycaemia and L-dopa gave variable responses. In one case, substitutive thyroid hormone therapy restored the GH response to L-dopa and arginine hydrochloride to normal. Paradoxically, GH increase following stimulation with TRH.

Adolescent↗
PubMed1977

Asymptomatic autoimmune thyroiditis and coronary heart-disease. Cross-sectional and prospective studies.

Cross sectional and prospective surveys of thyroid autoimmunity have been performed in two cohorts of men, 280 living in west Finland and 269 in east Finland. In both populations, aged 50 to 69 years at the first survey, risk factors for coronary heart-disease (C.H.D.) were common. The incidence of C.H.D. was shown to be related to the presence of thyroid antibodies. The results of the cross-sectional studies were not conclusive. The five-year follow-up study emphasised that in both areas asymptomatic thyroid autoimmunity, independently of other known risk factors, was a predictor of subsequent development of C.H.D. The importance of asymptomatic autoimmune thyroid-itis as a risk factor for C.H.D. increases with age.

Aged↗
PubMed1976

Pituitary and extrapituitary effects of somatostatin in normal man.

The effects of synthetic linear somatostatin on basal circulating levels on several pituitary and pancreatic hormones, and of glucose and free fatty acids (FFA) were studied in 6 normal men after an overnight fast. A priming intravenous infusion of 250 mug of somatostatin in 18 sec was followed by a constant infusion of 500 mug over a period of 60 min. A decrease in plasma values of GH, prolactin, TSH, insulin and glucagon and in blood glucose was observed during somatostatin infusion, while FFA levels increased progressively. Plasma IRI and blood glucose increased rapidly when the somatostatin infusion was stopped, while FFA decreased progressively; GH, prolactin, TSH and glucagon remained low as compared to basal levels for one hour after the end of the infusion, i.e. until the end of the experiment. A slight but significant increase of LH and ACTH was observed after the end of the infusion.

Adrenocorticotropic Hormone↗