bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of thyrotrophin receptors in human thyroid membranes
Authors: de Bruin Tjerk W. A. , van der Heide Daan 
Published: December 2008

Abstract.
The influence of pH, salts, temperature and time of incubation on the binding of [125I]thyrotrophin to its human thyroid receptor was studied. Optimal binding was achieved at pH 7.0–7.6. Pre-incubation of membrane receptors at pH 6.0 resulted in a 60% loss of binding. There was dynamic equilibrium, as demonstrated by kinetic experiments. Scatchard analysis yielded non-linear plots with apparent affinity constants of 1.9 × 109 m−1 and 3.7 × 107 m−1. The concentration of [125I]thyrotrophin used in the experiments (1.2–2.2 pm) approximated normal human serum thyrotrophin concentration.
Refractoriness of TSH- and PGE2-stimulated iodine metabolism in cultured porcine thyroid cells, evidence for refractoriness at the level of cAMP action
Authors: Takasu Nobuyuki , Sato Akira , Yamada Takashi , Shimizu Yoshifusa 
Published: December 2008

Abstract.
In an attempt to study intrinsic regulatory mechanism involved in iodine metabolism, chronic and acute effects of TSH, PGE2 and DBC on iodine uptake, iodide discharge and organic binding of iodine were examined using cultured porcine thyroid cells.
Culture in the presence of TSH, PGE2 and DBC for 6 days maintained the ability of thyroid cells to take up iodide and organify it, but culture in the absence of these substances failed to do so. When incubated with Nal in the presence of 1 mm methylmercaptoimidazole (MMI), the cells took up iodide and this accumulated iodide was discharged by TSH, PGE2 and DBC. TSH-, PGE2- and DBC-stimulated iodide discharge was depressed greatly after chronic exposure to TSH, PGE2 or DBC. This refractoriness of TSH-, PGE2- or DBC-stimulated iodide dishcarge was not specific for each thyroid stimulating substance; previous exposure to TSH, PGE2 or DBC induced refractoriness of TSH-, PGE2- and DBC-stimulated iodide discharge, providing evidence for the existence of refractoriness at the level of cyclic AMP action on iodide discharge. When incubated with Nal in the absence of MMI, the cells took up iodide and organified it. After 30 min incubation with Nal, TSH, PGE2 and DBC were added and they stimulated iodide organification further. This TSH-, and PGE2-stimulated iodide organification was also depressed after exposure to TSH or PGE2.
These data indicate that, as an intrinsic regulatory mechanism, refractoriness is operating at the level of cAMP action on iodine discharge and organification.
Maturation of renal and hepatic monodeiodination of thyroxine to triiodothyronine and post-natal changes of serum thyroid hormones in young rats
Authors: Suzuki Yukichi , Kita Kyoko , Uchigata Yasuko , Takata Ikuro , Sato Tamotu 
Published: December 2008

Abstract.
Maturational changes of renal and hepatic 5′-monodeiodination of thyroxine (T4) and post-natal changes of serum thyroid hormone levels were investigated in young rats under 35 days of age. Renal T3 generation in the 1-day-old rats was low, rose progressively to a level of more than 200% of the adult rats on days 21 and 28 and declined thereafter. In contrast, hepatic T3 generation increased from an initial low activity to a plateau after 7 days of age, which was 1½ times higher than that of adult rats. Because of the extremely low value of serum T4 in the neonatal period, T3/T4 and rT3/T4 ratios were elevated on day 7. The ratio of rT3/T4 decreased gradually and became stable after 21 days of age, while the T3/T4 ratio increased reciprocally to a peak on days 21 and 28, corresponding to the period of maximal activity of renal T4 monodeiodination. These results indicate that in addition to elevated hepatic T4 monodeiodination, renal conversion of T4 to T3 may play a significant physiological role during the period of enhanced T3 requirement for maturation.
Treatment with cimetidine in patients with primary hyperparathyroidism
Authors: Ljunghall Sverker , Åkerström Göran , Rudberg Claes , Selking Orjan , Johansson Henry , Wide Leif 
Published: December 2008

Abstract.
Treatment with cimetidine (1000 mg daily in four divided doses) was given for 3–20 weeks to 10 patients with primary hyperparathyoidism (HPT). All patients had hypercalcaemia and raised serum concentrations of parathyroid hormone (PTH). During treatment no consistent effects were noted on either serum calcium or PTH and normalization did not occur in any case. Hypergastrinaemia was demonstrated in 6 patients and was also unaffected by therapy while in the 4 patients with normal pre-treatment gastrin values a slight increase was seen.
This study does not support the view that cimetidine can be of use for the treatment of primary HPT.
Acetate: inhibitor of growth hormone hypersecretion in diabetic and non-diabetic uraemic subjects
Authors: Ørskov Hans , Hansen Aage Prange , Hansen Hans Erik , Alberti K. George M. M. , Noy George A. , Nosadini Romano 
Published: December 2008

Abstract.
Five diabetic and 14 non-diabetic uraemic patients on long-term haemodialysis were studied during twenty-one 24 h periods including 5 to 7 h of haemodialysis against glucose-free acetate buffered dialysis fluid. Half-hourly blood samples were collected for hormonal and metabolite analysis. In addition, blood samples were analyzed in 40 experiments covering the haemodialysis and a pre-dialysis period. Before dialysis, plasma growth hormone levels were high and fluctuating, but almost always fell to low normal values within the first 2 h of haemodialysis.
In the diabetic uraemic patients, the occasional severe hypoglycaemic episodes occurring during haemodialysis did not provoke growth hormone release, and hypoglycaemic reactions were not encountered.
Intravenous acetate infusion studies resulted in plasma concentrations ranging from 1.3 to 2.7 mmol, i.e. about 60 per cent of the levels reached during haemodialysis and in suppression of growth hormone secretion. It is suggested that the fall in growth hormone levels and the lack of hypoglycaemic symptoms during haemodialysis is due to the use of acetate as a fuel in brain.
Isolated ACTH deficiency and primary hypothyroidism
Authors: Miller Michael J. , Horst Tomm Vander 
Published: December 2008

Abstract.
A patient presented with severe primary hypothyroidism and secondary adrenal insufficiency due to the isolated deficiency of ACTH. The diagnostic evidence suggests that both are of an autoimmune aetiology. Acquired isolated or unitrophic ACTH deficiency is a rare but definite cause of adrenal insufficiency. Additional case reports and autopsy studies describing acquired isolated ACTH deficiency associated with autoimmune thyroid disease have appeared in the literature suggesting that the association is more than coincidental. Combined thyroid and adrenal failure should not always be considered to be the result of combined end organ failure. Unitrophic isolated ACTH deficiency may co-exist with primary hypothyroidism.
Plasma noradrenaline and adrenaline in pre-eclampsia, essential hypertension in pregnancy and normotensive pregnant control subjects
Authors: Pedersen E. B. , Rasmussen A. B. , Christensen N.J. , Johannesen P. , Lauritsen J. G. , Kristensen S. , Wohlert M. 
Published: December 2008

Abstract.
Noradrenaline and adrenaline in plasma were determined in 15 patients with pre-eclampsia, 10 pregnant patients with essential hypertension, 2 patients with transient hypertension in pregnancy, 11 normotensive pregnant control subjects, and 16 non-pregnant normotensive control subjects. Measurements were performed in the second and third trimester, 5 days, and 3 months after delivery. Comparison within groups showed no significant differences in plasma noradrenaline or adrenaline between levels in pregnancy, 5 days after delivery, and 3 months after delivery in neither pre-eclampsia, essential hypertension nor normotensive pregnant control subjects. Comparison between groups showed no significant differences between the levels in pre-eclampsia, essential hypertension and normotensive pregnant control subjects, neither in pregnancy nor after delivery. Plasma noradrenaline and adrenaline in pregnancy were the same as in normotensive non-pregnant control subjects. Plasma noradrenaline and blood pressure were not correlated in any of the groups. It is concluded that the sympathetic adrenergic activity evaluated by plasma catecholamines is normal in patients with pre-eclampsia and pregnant patients with essential hypertension.
The concentration of progesterone, 20α-dihydroprogesterone, testosterone, oestrone and oestradiol-17β in serum, amniotic fluid and placental tissue of pregnant rabbits
Authors: Lau I. F. , Saksena S. K. , Salmonsen R. 
Published: December 2008

Abstract.
The concentrations of progesterone (Δ4P), 20α-dihydroprogesterone (20α-DHP), testosterone (T), oestrone (E1) and oestradiol-17β (E2β) in peripheral blood serum (PBS), amniotic fluid (AF) and placental tissue of rabbits during gestation were determined by radioimmunoassay. The placenta of the 10-day pregnant rabbit was fragile and composed mainly of maternal tissue. By the 12th day of pregnancy it was separable into maternal and foetal placentae. The mean concentration of Δ4P in PBS rose from 200 pg/ml (day 1 of pregnancy) to 17–21 ng/ml (days 10–15) and decreased gradually to 1 ng/ml a few hours before parturition. The 20α-DHP in PBS also showed an increase from 1.5 ng/ml (day 1) to 12 ng/ml (day 6) but fluctuated thereafter. The concentration of 20α-DHP in the PBS tended to be lower than that of Δ4P during pregnancy until the regression of the corpus luteum. An interesting observation was an increase of T on days 6–8 of pregnancy, the time when implantation occurs. The concentrations of E1 and E2β in PBS remained very low throughout pregnancy. Δ4P and 20α-DHP in AF ranged between 25 pg to 1 ng/ml and in no case during the course of pregnancy were the levels of T, E1 and E2β in AF higher than in PBS. Where the maternal placental Δ4P content remained between 1–2 ng/placenta, the foetal placenta Δ4P rose to a level of 15 ng/placenta by day 31 of pregnancy. A similar trend was recorded for 20α-DHP content. It is concluded that although a parallelism between PBS and myometrial steroid concentration was observed, no relationship could be drawn between the concentrations of steroid in PBS and those of the placental tissue and AF.
Steroid metabolism by a tumour of the specific gonadal stroma in a child
Authors: de Niepomniszcze Alicia Barmach , Rivarola Marco A. , Chemes Héctor E. , Bergadá César 
Published: December 2008

Abstract.
A study of steroid metabolism by a tumour of the specific gonadal stroma was carried out in a 10 year old boy. Tumours developed in the two testes from multiple foci, and clinically, no signs of sexual development were evident. Four testicular enzymes necessary for testosterone biosynthesis were estimated in the child, in two adult controls, and in three pre-pubertal boys with male pseudohermaphroditism but normal tests of Leydig cell function. 17α-Hydroxylase and 17β-hydroxysteroid dehydrogenase were similar in the five controls and in the gonad with the tumour, while 17,20-desmolase and 3β-hydroxysteroid dehydrogenase were grossly deficient in the child with the tumour. These enzyme deficiencies might explain the absence of peripheral virilization in a boy with a tumour of Leydig and Sertoli cells.
Vast release of submaxillary mouse renin to saliva after stimulation with cholinergic, β-adrenergic but especially α-adrenergic agonists
Authors: Pedersen Erik Bækkelund , Poulsen Knud 
Published: December 2008

Abstract.
α-adrenergic stimulation with phenylephrine causes release of vast amounts of mouse submaxillary gland renin to saliva. The amount released is about 100-fold higher than that released after β-adrenergic stimulation with isoproterenol and about 1000-fold higher than the amount released after cholinergic stimulation with pilocarpine. α-blockade with phenoxybenzamine before phenylephrine stimulation strongly inhibits the renin release. However, phenoxybenzamine or β-blockade with propranolol before isoproterenol stimulation have no effect on the amount of renin released. Thus, the release of submaxillary mouse renin to saliva is triggered mainly by activation of α-adrenergic receptors. Renin in cholinergic and α- and β-adrenergic stimulated saliva has the same molecular weight and the same specific enzymatic activity as renin in the submaxillary gland. This indicates that renin is secreted to saliva, and probably also to the blood, in its fully enzymically active 40 000 mol. wt. form regardless of the stimulus used.
The vast amounts of renin released to saliva (up to 600 Goldblatt Units) demonstrate that submaxillary mouse renin is secreted predominantly to saliva and much less to the blood. The mouse submaxillary gland therefore seems to have an exocrine rather than an endocrine role for release of renin.
Effect of bromocriptine and metergoline in the treatment of hyperprolactinaemic states
Authors: Ambrosi Bruno , Travaglini Pietro , Moriondo Paola , Nissim Marina , Nava Claudio , Bochicchio Domenico , Faglia Giovanni 
Published: December 2008

Abstract.
The effects of bromocriptine or metergoline treatment were evaluated in 80 hyperprolactinaemic patients (62 women and 18 men). The patients were subdivided into 4 groups: group A) 16 women with idiopathic hyperprolactinaemia; group B) 19 women with untreated Prl-secreting microadenomas; group C) 27 women with unsuccessfully operated prolactinomas; group D) 18 men with unsuccessfully treated macroprolactinomas. Sixty-eight patients were given bromocriptine (2.5–20 mg/day) for 3–58 months and 33 patients were given metergoline (4–16 mg/day) for 3–19 months. Bromocriptine and metergoline were equally effective in the treatment of functional hyperprolactinaemia and of untreated microadenomas, while bromocriptine showed a more potent Prl-lowering effect than metergoline in patients with higher Prl levels and large prolactinomas; both drugs restored the gonadal function to a similar extent, though metergoline was effective in some cases, even in the absence of full Prl suppression. Bromocriptine seems to exert an antitumoral effect, as documented by CT scan in some patients with macroadenomas, but the precise role of both drugs with respect to dose, length of treatment and effectiveness after withdrawal needs to be evaluated further.
Circadian rhythm of mitotic activity in normal and hyperplastic rat thyroid
Authors: Wynford-Thomas D. , Stringer B. M. J. , Williams E. D. 
Published: December 2008

Abstract.
This study was designed to provide a reliable quantitative assessment of the circadian rhythm of mitotic activity in the follicular cell population of the rat thyroid, and the effect on this rhythm of prolonged stimulation by a raised level of circulating TSH, induced by goitrogen administration.
Mitotic activity in groups of control and goitrogen-treated rats was assessed by a stathmokinetic technique during four 4-h periods spaced equally through one 24-h cycle. Particular attention was paid to the method of sampling to eliminate systematic and minimise random errors, and to the assesment of rhythmicity which was carried out by an appropriate statistical method.
A highly significant circadian rhythm was found in control animals with a daytime peak (12.00 to 16.00 h). Goitrogen treatment led to a 5- to 6-fold increase in the mean but a loss of detectable rhythmicity.
The results show that the presence and timing of this circadian rhythm must be taken into account in future studies of thyroid growth, and they throw some light on the possible mechanisms of its control. Comparison of the rhythm with that of serum TSH reported previously raises the possibility of a dominant control by this hormone even in euthyroid animals and suggests that it may act on cells in the G2 and/or G1/G0 phases of the cell cycle.
Effects of dexamethasone on the hypothalamic-pituitary-thyroid axis in rats
Authors: Mitsuma Terunori , Nogimori Tsuyoshi 
Published: December 2008

Abstract.
Effects of dexamethasone on the hypothalamic-pituitary-thyroid axis in rats were studied. Rats given saline (group A), 25 μg of dexamethasone/100 g body weight (group B) or 500 μg of dexamethasone/100 g body weight (group C) were serially decapitated and brain tissues and blood were obtained. TRH contents in the hypothalamus, plasma concentrations of TRH, TSH, T4, T3 and reverse T3 were measured by specific radioimmunoassay. TRH contents in the hypothalamus were significantly increased at 3 h in group B after dexamethasone treatment. In group C, however, they significantly increased for 1 to 3 h, but then decreased with the minimum at 20 h. TRH plasma levels significantly increased with the maximum at 4 h in group B and at 24 h in group C. TSH plasma levels were significantly decreased initially and then significantly increased with the maximum at 5 h in group B and at 24 h in group C. TSH responsiveness to TRH was significantly decreased at 1 to 3 h in group B, but in group C it was significantly decreased initially and then significantly increased. T3 plasma levels significantly decreased at 1 to 3 h in group B and at 1 to 18 h in group C. Reverse T3 plasma levels were significantly increased with the maximum at 3 h in group B and at 6 h in group C.
The results demonstrate that dexamethasone may act on multiple sites of the hypothalamic-pituitary-thyroid axis in rats and that its effect depends on the dose used or the time interval after dexamethasone treatment.
Radioimmunoassay for 13, 14-dihydro-15-ketoprostaglandin F2α and its application in normo- and anovulatory women
Authors: Schlegel Werner , Urdinola Jaime , Schneider Hermann P. G. 
Published: December 2008

Abstract.
Highly specific antibodies to 13, 14-dihydro-15-ketoprostaglandin F2α (PGFM) were raised in rabbits. The animals were immunized with PGFM-bovine serum albumin (BSA)-conjugates.
Prior to the incubation procedure PGFM was extracted by a rapid method with dichloromethane followed by column chromatography.
The antisera dilution was 1:10000 and the cross-reactivity towards prostaglandin A2, E2, F2α, 13, 14-dihydro-15-ketoprostaglandin E2 and the 15-ketoprostaglandin E2 and F2α was < 1%. The limit of detection was 1.9 ± 0.6 pg/ml plasma over the standard range 1.9–250 pg. The intra- and inter-assay variations were 3.9 and 15%, respectively.
PGFM was measured throughout the menstrual cycle in female volunteers.
In normal ovulatory women (n = 3) plasma levels of PGFM varied between 65.6 to 107.1 pg/ml.
No significant variations of plasma PGFM were seen during the cycle. In anovulatory women (n = 4) no difference of PGFM was found during the cycle. PGFM levels in hyperprolactinaemic but ovulating women tend to be higher than in anovulatory, and normoprolactinaemic subjects.
These data strongly indicate that PGFM is not correlated with other hormonal parameters tested here in the normal and anovulatory cycles.
The 'boar taint' steroid 5α-androst-16-en-3-one: an immunisation trial
Authors: Shenoy E. V. B. , Daniel M. J. , Box P. G. 
Published: December 2008

Abstract.
Entire and castrated male pigs were actively immunised against the steroid 5α-androst-16-en-3-one (androstenone) conjugated to bovine thyroglobulin as its carrier protein. This immunogen was incorporated with either Freund's complete adjuvant or a water-in-oil emulsion adjuvant; only the latter was found to be acceptable in the pig tissue.
Levels of free and antibody-bound androstenone were measured in the plasma of immunised and control boars. In the controls, levels of free androstenone rose from 15 ng/ml at 13 weeks old to 36 ng/ml at 27 weeks. In the immunised boars, levels of free steroid fell from 16 ng/ml at 13 weeks old to zero at 17 weeks old while levels of antibody-bound androstenone rose from zero at 13 weeks old to a mean level of 70 ng/ml at 27 weeks.
When immunised and control boars and non-immunised gilts were killed at 135 kg live weight, the levels of androstenone in their carcass fat were measured. Their meat was also subjected to organoleptic testing at the Meat Research Institute, Langford. Meat from animals whose fat contained significant levels of androstenone (0.4–1.6 μg/g) was found to taste of 'boar taint' while meat from control gilts with low fat levels of the steroid (0.1–0.2 μg/g) tasted normal.
The uptake of [3H]androstenone was compared in 12 separate body tissues of one immunised and one control boar. No significant differences were found. The presence of specific antibody in the immunised boar had not inhibited movement of steroid between plasma and body tissue.
Some hypotheses raised by these findings are discussed and the likelihood of successfully using immunisation against 'boar taint' is examined and questioned.
Further evidence for calcitonin gene duplication: the identification of two different calcitonins in a fish, a reptile and two mammals
Authors: Cano R. Perez , Girgis S. I. , Maclntyre I. 
Published: December 2008

Abstract.
In order to investigate the possibility of the simultaneous expression of two different calcitonin genes during evolution, we studied the nature of calcitonin in: eel pericardium, salamander branchial region, rat thyroid, ox thyroid, medullary carcinoma of the human thyroid and human thyrotoxic goitre.
Sensitive and specific RIAs for human calcitonin (hCT) and salmon calcitonin (sCT) were used in combination with high pressure liquid chromatography (HPLC).
We found that two different immunoreactive calcitonins resembling hCT and sCT exist in eels, salamanders and rats. The major form is i-sCT-like in eels and salamanders, while it is i-hCT-like in rats. Extracts of ox thyroid contained, in addition to the major artiodactyl-CT, an i-hCT-like material. The various human thyroid extracts studied, contained i-hCT but no i-sCT-like material.
This study demonstrates the simultaneous expression of two different calcitonin genes in several species. Taken with the presence of molecules resembling sCT and hCT in birds, this further evidence is consistent with duplication of the calcitonin gene early in vertebrate evolution.
Restoration of the LH surge and ovulation by insulin in alloxan-diabetic immature rats treated with pregnant mare's serum gonadotrophin
Authors: Kirchick Howard J. , Keyes P. Landis , Frye Billy E. 
Published: December 2008

Abstract.
Immature alloxan-diabetic rats injected with pregnant mare's serum gonadotrophin (PMSG) do not ovulate and the LH surge is absent. In the present studies we have examined the effects of several insulin treatments on the LH surge and ovulation in alloxan-diabetic rats. Rats were made diabetic by injection of alloxan on day 24 of age. Only those rats with fasting blood glucose concentrations exceeding 180 mg/100 ml on day 27 were considered diabetic. PMSG was injected on day 30. Rats received insulin either by injection (2, 3, 4 or 6 IU/100 g/day; Ultralente B.I.D.) or by subcutaneous implants (Alzet osmotic minipumps; 1.8 or 2.4 IU/day). None of the diabetic rats without insulin treatment ovulated. Some of the animals in each insulin treatment group ovulated, however, the percentage of animals ovulating was highly variable from experiment to experiment when the insulin was given by injection. When insulin was administered by osmotic minipump, the results were more consistent, with at least 60% of the rats ovulating in each experiment. LH surges were found on the afternoon of presumed pro-oestrus (day 32) in diabetic insulin-treated rats which ovulated. In confirmation of previous results, rats without insulin treatment did not have LH surges. Although the site of insulin action has not been determined, these data indicate that the LH surge mechanism in the immature PMSG-treated rat is insulin-dependent.