bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of rT3 5'-monodeiodination in rat brain: comparison with T4 and T3 5-monodeiodinations
Authors: Tanaka Kiyoshi , Inada Mitsuo , Mashio Yasuo , Ishii Hitoshi , Naito Koichi , Nishikawa Mitsushige , Takahashi Kiyoyuki , Imura Hiroo 
Published: December 2008

Abstract.
The present study revealed the existence and some characteristics of rT3 5'-deiodinase in rat brain by measuring the production of 3,3'-T2 from rT3 by radioimmunoassay. The conversion of rT3 to 3,3'-T2 was dependent on the duration of the incubation, tissue amount, temperature and pH (the optimal pH was 8.0), suggesting its enzymatic nature. Apparent Km was estimated to be 0.16 μm and the Vmax was 139.3 fmol/mg protein/min. The converting activity was dependent on the concentration of dithiothreitol (DTT). In contrast to T4 or T3 5-deiodinase, rT3 5'-deiodinase activity in the rat brain was the highest in cerebellum and the activity was low in the neonatal rat brain. Moreover, the 5'-deiodinase activity was inhibited by propylthiouracil (PTU). These differences between rT3 5'-deiodinase and T4 or T3 5-deiodinase suggest that different deiodinases are present in rat brain, and that local conversion of thyroid hormone is important for its action in the central nervous system.
Impaired subcutaneous absorption of insulin in 'brittle' diabetics
Authors: Home P. D. , Massi-Benedetti M. , Gill G. V. , Capaldo B. , Shepherd G. A. A. , Alberti K. G. M. M. 
Published: December 2008

Abstract.
Twenty-four hour plasma free insulin and blood glucose and intermediary metabolite profiles have been measured in 6 C-peptide deficient 'brittle' diabetic patients, during continuous sc and im insulin infusion. During sc infusion free insulin profiles were erratic and unpredictable. Mean 24 h blood glucose levels were raised at 12.6 ± 2.1 (se) mmol/l, and 3-hydroxybutyrate at 0.24 ± 0.08 mmol/1. Blood lactate (1.88 ± 0.18 mmol/l) and glycerol (0.084 ± 0.007) were also elevated. Insulin (im) restored free insulin profiles to the normal pattern as found in 'stable' diabetics on sc infusion, with characteristic post-meal peaks (49 ± 7, 103 ± 35, and 95 ± 34 mU/l) and stable night-time levels. Mean 24 h blood glucose was 6.7 ± 1.1 mmol/l (P < 0.05 compared to sc infusion) and 3-hydroxybutyrate 0.07 ± 0.02 mmol/l (P < 0.05). Blood lactate (1.67 ± 0.08 mmol/l) and glycerol (0.10 ± 0.02 mmol/l) levels remained abnormal. The ratio of plasma free insulin to insulin dose administered was significantly higher during im infusion. In the 6 'stable' diabetics on sc insulin infusion good blood glucose control (7.1 ± 0.9 mmol/l) was accompanied by clear post-prandial insulin peaks, and stable nocturnal levels. The results strongly suggest that in one category of 'brittle' diabetics there is defective and erratic sc insulin absorption.
The pituitary-testicular axis of uraemic subjects on haemodialysis and continuous ambulatory peritoneal dialysis
Authors: Semple C. G. , Beastall G. H. , Henderson I. S. , Thomson J. A. , Kennedy A. C. 
Published: December 2008

Abstract.
Pituitary-testicular function was evaluated in 18 patients with chronic renal failure, 9 treated by maintenance haemodialysis (HD) and 9 by continuous ambulatory peritoneal dialysis (CAPD), and compared with a non-uraemic control group. Serum total testosterone and the free testosterone index were significantly low in both dialysis groups. Basal FSH and LH levels were elevated but this reached significance only with regard to LH. The responses of both FSH and LH to the iv administration of LRH were normal. There was no significant difference between the CAPD and HD groups in any of the hormonal parameters estimated. While CAPD may improve control of some metabolic parameters when compared with HD, it does not improve the function of the pituitary-testicular axis.
Potent 48 hours inhibition of prolactin secretion by pergolide in hyperprolactinaemic women
Authors: L'Hermite Marc , Debusschere Pierre 
Published: December 2008

Abstract.
The duration of the inhibition of Prl secretion by pergolide, a new dopaminergic ergoline, was investigated in 5 hyperprolactinaemic women after a single oral 50 μg dose. In each subject, blood samples were collected every 2 h for 18–24 h to establish baseline Prl level and then every 3 h for 48–51 h after pergolide administration. In each subject, levels were potently suppressed by at least 80% of baseline and brought down to the normal range. Prolactin suppression was quite sustained throughout the study period in 4 patients and to a lesser degree in the remaining subject.
This potent long-lasting inhibition of Prl secretion should enhance the efficacy and acceptability of the chronic treatment of hyperprolactinaemia with this new dopamine agonist and, for example, allow drug intake only once every other day.
Impaired pituitary response to bromocriptine suppression: reversal after bromocriptine plus tamoxifen
Authors: Völker Wernfrid , Gehring Werner G. , Berning Renate , Schmidt Rüdiger C. , Schneider Jörg , von zur Mühlen Alexander 
Published: December 2008

Abstract.
This study was designed to clarify whether previously resistant cases of adenomatous hyperprolactinaemia to bromocriptine might be improved by additive tamoxifen therapy. Ten hyperprolactinaemic women under bromocriptine (2.5–10 mg) with hypophyseal tumours of different extent were treated with a combined therapy of bromocriptine and tamoxifen (10–20 mg). Two of them had undergone incomplete resection of chromophobe adenomata. The others refused surgery or irradiation. Two other women without basal therapy because of side effects from bromocriptine, received the combined therapy from the beginning of the study. In 6 out of 10 women the addition of tamoxifen resulted in a marked suppression of prolactin serum values. Amenorrhoea and glactorrhoea ceased in 4 of them. One woman conceived. One reported a marked improvement of libido. One stated that side effects under bromocriptine disappeared through the addition of tamoxifen. The 2 women who previously were suffering from side effects were able to take bromocriptine when tamoxifen was added. Four patients were non-responders. Serum prolactin remained unchanged as well as the clinical follow-up. The effectiveness of the combined therapy was not related to the extent of the tumour or to the clinical or biochemical baseline date.
We conclude that the suppressive effect of bromocriptine on prolactin secretion is enhanced by the addition of tamoxifen in most cases of adenomatous hyperprolactinaemia. Side effects of bromocriptine are considerably reduced. Anti-oestrogens are competitive inhibitors of the binding of oestradiol to the receptor. Oestrogen play an important role in the development of prolactin secreting adenomata. Our finding of responders and non-responders to tamoxifen suggests that the anti-oestrogen competes for greater or lesser concentrations of receptor sites in prolactinomata.
Time course of inhibition of synthesis and basal release of FSH from pituitary glands of female rats by bovine follicular fluid in vitro
Authors: Jenner A. A. J. , de Koning J. , van Rees G. P. 
Published: December 2008

Abstract.
Inhibin-like activity in steroid-free bovine follicular fluid (bFF) is demonstrated using an in vitro technique with hemi-pituitary glands from intact female (second day of dioestrus) and ovariectomized rats: synthesis as well as basal release of FSH, but not of LH, are inhibited profoundly. The results confirm and extend data from other investigators on the action of inhibin-like material. The effect of the inhibin-like activity is shown to be reversible, as synthesis and the rise of basal release are restored when bFF is withdrawn from the incubation medium. Synthesis of FSH seems to be inhibited earlier than basal release, and it is suggested that the inhibin-like material acts only directly on FSH synthesis. Some possibilities of the mechanisms of action of inhibin-like activity are discussed.
A longitudinal study of serum TSH, and total and free iodothyronines during normal pregnancy
Authors: Weeke J. , Dybkjær L. , Granlie K. , Jensen S. Eskjær , Kjærulff E. , Laurberg P. , Magnusson B. 
Published: December 2008

Abstract.
Serum T4, T3, rT3, free T4, free T3 and TSH were measured during and after normal pregnancy in 20 women. Special methodological precautions were taken to avoid interference of other hormones and protein alterations in the assays. Serum T4 and T3 were steadily increasing during the last part of the 1st trimester, and remained high and nearly stable during the 2nd and 3rd trimester of the gestation period. The high levels were approximately 1.5 times the values measured 10 weeks post-partum. Serum rT3 was elevated already during the last part of the 1st trimester and remained high throughout pregnancy, compared to the post-partum value. Serum free T4 and free T3 were slightly elevated in early pregnancy. The values decreased gradually during pregnancy and were slightly depressed during the 3rd trimester. A gradual increase in serum TSH was observed during pregnancy and the 2nd and 3rd trimester values were significantly higher than the post-partum value. The mean values for serum TSH, free T4 and free T3 remained always well within the normal range. Thus small variations in serum free iodothyronines and TSH occur during normal pregnancy, the alterations observed in the last trimester of the gestation period resembling those of a slight thyroid insufficiency. These trends in variation of the reference values are worth to remember in the diagnosis of borderline hypo- or hyperthyroidism and in the balanced treatment of pregnant women with thyroid dysfunction.
Impaired secretion of TSH in critically ill patients with 'low T4-syndrome'
Authors: Vierhapper Heinrich , Laggner Anton , Waldhäusl Werner , Grubeck-Loebenstein Beatrix , Kleinberger Gunther 
Published: December 2008

Abstract.
Thyroid and pituitary function was studied in 10 male and 6 patients female during critical non-endocrine disease. Low concentrations of TT3 were observed in each case. Seven patients out of whom 3 survived, presented with low levels of TT4 due to deficiency in TBG in the presence of normal values of FTI and FT4, whereas a 'low T4-syndrome', characterized by low concentrations of both TT4 and FT4 was seen in 9 patients, 8 of whom died 1 to 16 days after evaluation of pituitary function. A diminished response of TSH to iv TRH (400 μg), as observed in 4 patients with normal FT4 and in all patients with 'low T4-syndrome', was not accompanied by a concomitant lack in stimulated release of LH, FSH and Prl in the majority of cases. However, the secretory maximum of LH and FSH following stimulation by LRH (100 μg iv) was delayed in 10 and in 9 patients, respectively, including patients both with normal and subnormal concentrations of FT4. From the above it appears that low stimulated concentrations of TSH in the presence of subnormal concentrations of FT4 indicate an extremely poor prognosis in critically ill patients. The abnormal behaviour of TSH in this group of patients cannot be explained by generalized pituitary insufficiency or by an increase in FT4.
Effects of seven different oestrogen sulphates on uterine growth and on progesterone receptor in the foetal uterus of guinea pig after administration to the mother
Authors: Pasqualini J. R. , Lanzone A. , Tahri-Joutei A. , Nguyen B. L. 
Published: December 2008

Abstract.
The biological effect of seven different oestrogen sulphates: oestrone-3-sulphate (E1-3-S), oestradiol-3-sulphate (E2-3-S), oestradiol-17-sulphate (E2-17-S), oestradiol-3,17-disulphate (E23,17-DS), oestriol-3-sulphate (E3-3-S), oestriol-17-sulphate (E3-17-S), oestriol-3,16,17-trisulphate (E3-3,16,17-TS), was studied in the foetal uterus of guinea pig (55–65 days of gestation) after sc administration for 3 consecutive days of each sulphate to the mother. On day 4, two response parameters were investigated, the uterotrophic effect and the action on the progesterone receptor. The monosulphates at the C3 position of the oestrogens (E1-3-S, E2-3-S and E3-3-S) provoked an increase in uterine weight of 1.9–2.4 times in relation to the non-treated animals. These oestrogen sulphates also very significantly stimulated the number of progesterone specific binding sites, 7–10 times in relation to the non-treated animals. On the other hand, when the sulphate was at C17 of the oestrogens (E2-17-S, E3-17-S, E2-3, 17-DS, E3-3,16,17-TS), very little or no effect on the foetal uterus was observed on the two parameters studied.
It is concluded that oestrogen (oestrone, oestradiol, oestriol) sulphates in position C3 can be involved in the biological response to the hormone and it is suggested that the effect is carried out after the hydrolysis of the sulphate. On the other hand, sulphates in C17 are not hydrolysed and no significant biological effects were observed in the uterine growth or in the progesterone receptor.
β-endorphin-like peptides in autopsy pituitaries from adults, neonates and foetuses
Authors: Vuolteenaho Olli , Leppäluoto Juhani , Höyhtyä Matti , Hirvonen Jorma 
Published: December 2008

Abstract.
The presence of β-endorphin in human pituitary was studied using radioimmunoassay, opiate receptor binding assay and different chromatographic methods. Adult human pituitaries were found to contain 291 ± 59 μg/g β-endorphin immunoreactivity, of which 15–45% eluted like β-endorphin in Sephadex G-75 gel filtration. The yield of β-endorphin immunoreactivity was found to be dependent of the extraction method used, but the relative proportion of the different immunoreactive components (proopiomelanocortin, β-lipotrophin and β-endorphin) was approximately identical irrespective of the extraction method. No correlation was observed between the time lag from death to autopsy (within 7 days) and either the total amount of β-endorphin immunoreactivity or the β-lipotrophin/β-endorphin ratio in the acid extracts of human pituitaries. Repeated freezing and thawing was found to cause a progressive loss of extractable β-endorphin immunoreactivity so that the smaller molecular weight material (β-endorphin) disappeared more rapidly than the higher molecular weight material (β-lipotrophin). Pituitaries from neonates and foetuses were found to contain proportionally more β-endorphin than pituitaries from adults (β-lipotrophin/β-endorphin ratio was 2.76 ± 0.43 in adults, 0.93 ± 0.11 in neonates and 0.47 ± 0.09 in foetuses). β-endorphin-like material from gel filtration was found to separate into two components on SP-Sephadex C-25 cation exchange chromatography. The more basic of these eluted identically with synthetic human β-endorphin in reversed phase HPLC, displaced tracer parallelly both in radioimmunoassay and opiate receptor binding assay and had a receptor binding potency not significantly different from that of synthetic β-endorphin. The less basic component has a smaller molecular weight than β-endorphin and represents a formerly unrecognized human pituitary endorphin-like peptide. The results suggest that β-endorphin is a naturally occurring peptide in human pituitary.
Anti-thyrotrophin receptor antibodies in Graves' disease as demonstrated directly by immunoprecipitation assay
Authors: de Bruin Tjerk W. A , van der Heide Daan , Krol Maria C. 
Published: December 2008

Abstract.
An immunoprecipitation assay was developed to determine the presence of antibodies against human TSH1 receptors. With this assay we were able to demonstrate that in comparison with sera from normal controls, 24 out of 30 (80%) sera from patients with untreated Graves' disease could immunoprecipitate more [125I]TSH-TSH receptor complexes. In 9 assays, an average of 14.1 ± 3.7% (sd) of the [125I]TSH-TSH receptor complexes was immunoprecipitated by the 30 Graves' sera vs 9.8 ± 3.0% by the normal pool serum (n = 23) (P < 0.001) and 7.7 ± 2.8% by the 22 normal sera (P < 0.001). One serum of the 24 positive Graves' sera was studied in detail. The results suggest that this serum contained an anti-TSH receptor auto-antibody directed towards a different determinant on the TSH receptor than the TSH binding site.
Studies of catecholamine effect on cyclic AMP in human cultured thyroid cells: their interaction with thyrotrophin receptor
Authors: Toccafondi Roberto S. , Brandi Maria Luisa , Rotella Carlo M. , Zonefrati Roberto 
Published: December 2008

Abstract.
Even though adrenergic nerve terminals between and around thyroid follicles and catecholamine stimulation of thyroid adenylate cyclase have been reported, there is no uniform concept on catecholamine interaction with thyrotrophin (TSH) receptors. Therefore, the effect of catecholamines on TSH-stimulated cyclic AMP (cAMP) accumulation in human follicular thyroid cells has been investigated, to thus eliminating the extrathyroidal actions of catecholamines.
Epinephrine, norepinephrine and isoproterenol appeared to be rapid and potent stimulators of intracellular cAMP accumulation, the half maximum increase doses being 4 × 10−7m, 1 × 10−5m and 5 × 10−7m, respectively. While propranolol (1 × 10−5m) prevented the stimulatory effect of catecholamines and failed to inhibit the effect of bovine TSH, phentolamine (1 × 10−5m) enhanced the potency of norepinephrine and bovine TSH, leaving that of epinephrine unchanged. The effects of epinephrine (2 × 10−8m) and isoproterenol (2 × 10−8m) were additive to that of bovine TSH (0.5 mU/ml), but the effect of simultaneous stimulation with norepinephrine (5 × 10−7m) and bovine TSH (0.5 mU/ml) was lower than expected. Prenalterol, a selective β1-agonist, did not stimulate cAMP accumulation, while terbutaline, a selective β2-agonist, exerted a potent stimulation. Metoprolol, a selective β1-adrenergic blocker, did not affect the response of thyroid follicular cells to isoproterenol.
These results demonstrate the existence of β-adrenergic receptors in human thyroid follicular cells, mainly of the type β2, apparently not correlated with TSH receptor. The existence of α-adrenergic receptors which counter-regulate TSH functional responses in human thyroid follicular cells is suggested.
The accumulation of [35S]methimazole by human and rat lymphocytes
Authors: Shewring G. S. , Lazarus J. H. 
Published: December 2008

Abstract.
The accumulation of 35S labelled methimazole (MMI) was examined in lymphocytes. No uptake of label was found in peripheral blood lymphocytes (PBL) from normal control subjects after in vitro incubation with the drug. Following administration of [35S]MMI to patients with Graves' hyperthyroidism PBL cell to plasma (C/P) 35S activity was greater than 1 in 4 of 11 patients and only in 1 of 7 other patients undergoing thyroidectomy. Thyroid lymphocytes from 2 of these patients showed some accumulation of activity.
Following administration of [35S]MMI to normal rats C/P 35S ratios ranged from 1–5.6 but no 35S accumulation was found in PBL or thyroid lymphocytes from August strain rats in which experimental autoimmune thyroiditis had been produced.
It is concluded that there is minimal, if any, significant accumulation of MMI in lymphocytes of patients with Graves' disease. The immunosuppressive action of MMI on lymphocyte antibody production must therefore by indirect.
Somatostatinoma syndrome: does a clinical entity exist?
Authors: Stacpoole Peter W. , Kasselberg A. G. , Berelowitz Michael , Chey William Y. 
Published: December 2008

Abstract.
We report here 2 patients with somatostatinsecreting tumours and hypersomatostatinaemia. One subject, a 36 year old woman with diabetes, flushing, labile blood pressure and diarrhoea, had elevated basal plasma levels of somatostatin-like immunoreactivity (SLIR) and calcitonin. Plasma SLIR increased further following tolbutamide administration. Plasma levels of prostaglandin E2 (PGE2) and pancreatic polypeptide (PP), normal in the basal state, showed exaggerated responses to pentagastrin and secretin, respectively. Immunocytochemistry of the tumour tissue revealed cells containing somatostatin-, calcitonin-, PGE2- and PP-like immunoreactivity. The other patient, a 52 year old male, had an SLIR-secreting tumour of the proximal duodenum and elevated basal and post-tolbutamide SLIR levels but no signs or symptoms suggestive of increased SLIR production. Tumour tissue revealed cells containing somatostatin- and calcitonin-like immunoreactivity.
We conclude that patients with somatostatinomas do not always exhibit a predictable syndrome. Patients with these tumours may exhibit a range of clinical, biochemical and immunocytochemical features typical of endocrine tumours of mixed-cell origin, such that the dominant signs and symptoms associated with these neoplasms cannot readily be ascribed to overproduction of any single hormone.
Pharmacological effects of 2- and 4-methyloestradiol as a probe to test the biological importance of 2- and 4-hydroxylation of oestrogens (catecholoestrogen-formation)
Authors: Ball Peter , Emons Günter , Haupt Otto , Knuppen Rudolf 
Published: December 2008

Abstract.
2-Methyloestradiol, 4-hydroxy-2-methyloestradiol and 4-methyloestradiol were synthesized and infused sc into long-term ovariectomized rats by means of osmotic minipumps. The effects on uterine growth and gonadotrophin release were tested and compared to oestradiol or vehicle alone. 2-Methyloestradiol and 4-hydroxy-2-methyloestradiol, steroids in which the 2-hydroxylation is selectively blocked, definitely increased uterine weight (dry and wet), decreased morning LH and increased evening LH serum levels. 4-Methyloestradiol, a compound which cannot be 4-hydroxylated in vivo, was inactive in the model used. It is assumed that 4-hydroxylation constitutes an essential step in the expression of oestrogenicity of primary oestrogens, whereas 2-hydroxylation does not.
A quantitative assay for the cytoplasmic androgen receptor using [3H]dihydrotestosterone in the presence of NAD+-nucleosidase
Authors: Moeller Hans , Oettling Günter , Fiederer Bernhard , Brügmann Gerd 
Published: December 2008

Abstract.
In prostatic cytosol DHT1 is metabolized to 5α-androstane-3α (or β), 17α-diols with a half life of 2 h even at 4°C. Thus, [3H]DHT appears to be a poor marker for a quantitative assessment of androgen receptors (AR). Methyltrienolone (R1881) seems to be advantageous as it is not metabolized. However, because of considerable binding to progestin receptors, assays using [3H]R1881 are not specific for AR in tissues containing progestin receptors. We, therefore, developed a specific assay for AR using [3H]DHT (14 nm) as marker, where metabolism of DHT is prevented by pre-incubation with NAD+-nucleosidase.
The [3H]DHT-receptor complex is separated from free, SHBG-bound and unspecifically bound [3H]DHT by agar gel electrophoresis. The binding sites of high affinity and low capacity are characterized by suppression with unlabelled R1881 (2 μm) in a parallel assay. Under these conditions DHT and R1881 appear to have the same kinetics of association and dissociation.
Weighted non-linear regression analysis of specific binding capacity at various ligand concentrations reveals that in rat prostatic cytosol the affinity of DHT (Kd = 0.405 ± 0.0839 nm) is significantly higher (P < 0.01) than that of R1881 (Kd = 1.25 ± 0.271 nm).
Sexual precocity in a boy due to hypersecretion of LH and prolactin by a pituitary adenoma
Authors: Faggiano M. , Criscuolo T. , Perrone L. , Quarto C. , Sinisi A. A. 
Published: December 2008

Abstract.
The paper reports on precocious puberty and galactorrhoea in a 4 8/12 year old boy. Roentgenograms of the skull showed slight lateral bulging of sella floor and pneumoencephalography indicated a pituitary adenoma with a suprasellar extension. Pre-operative study of anterior pituitary function was normal except for increased values of LH (900 mIU/ml), testosterone (2000 ng/ml) and prolactin (215 ng/ml). After removal of a chromophobe pituitary adenoma by transfrontal surgery the galactorrhoea disappeared within 10 days. Post-operative endocrine evaluation showed immediate normalization of LH, testosterone and prolactin values.