bluuebunny/crossref_metadata_2025_split huggingface dataset:
Circulating vitamin D metabolites and hypercalcaemia of malignancy
Authors: Ralston Stuart H. , Cowan Robert A. , Robertson Andrew G. , Gardner Mary D. , Boyle Iain T. 
Published: December 2008

Abstract. Plasma concentrations of 1.25 dihvdroxvcholecalciferol were measured in 44 patients with malignancy associated hvpercalcaemia and related to other hormonal regulators of calcium metabolism. Immunoreactive PTH concentrations were suppressed in all but 2 patients and, as a group, patients with hvpercalcaemia of malignancy had lower 1,25 dihydroxycholecalciferol concentrations than normocalcaemic cancer patients.
1,25 dihydroxycholecalciferol concentrations were clearly detectable in a significant proportion (43%) of hypercalcaemia cases however, suggesting that in these patients the active vitamin D metabolite may contribute to the pathogenesis and maintenance of the hypercalcaemia by stimulating bone resorption, and/or by increasing absorption of calcium from the intestine. Measurement of plasma 1,25 dihydroxycholecalciferol concentration does not provide a wholly reliable method for distinguishing the hypercalcaemia of malignancy from primary hyperparathyroidism.
Endocrine involvement in children with β-thalassaemia major. Transverse and longitudinal studies. I. Pituitary-thyroidal axis function and its correlation with serum ferritin levels
Authors: Cavallo L. , Licci D. , Acquafredda A. , Marranzini M. , Beccasio R. , Scardino M. L. , Altomare M. , Mastro F. , Sisto L. , Schettini F. 
Published: December 2008

Abstract. Thyroid function was investigated by a TRH test in 24 clinically prepubertal children, 3–15 years old with β-thalassaemia major; in 7 of them the test was repeated once and in 2 twice at intervals of at least 12 months. Basal T4, T3, TBG and TSH levels and the TSH levels during a TRH test were determined and correlated with age and serum ferritin levels.
Basal serum T4, T3 and TBG levels were lower and serum TSH levels were higher during the test and in the basal state in thalassaemia major children than in control children.
These results show a compensated sub-clinical primary hypothyroidism.
The transversal study did not show any significant correlation between the hormonal parameters studied and chronological age or serum ferritin levels.
In contrast, the longitudinal study showed a significant correlation between pituitary-thyroidal axis function and siderosis (positive correlations between the variations of TSH levels as Δ, peak, 30 and 45 min values and the variations of serum ferritin levels).
The thyroid impairment seems not to be correlated with serum ferritin levels in the transversal study because of the presence of an individual different sensitivity of the gland to the iron overload. The ferritin dependence of this impairment is shown only by longitudinal studies where individual differences in sensitivity of the gland are absent.
Therefore iron chelation by desferrioxamine sc infusions, resulting in a decrease of ferritin, improves the deficient thyroid function.
Steroid induced changes of the renal kallikrein-kinin system in rats
Authors: Bönner G. , Autenrieth R. , Marin-Grez M. , Speck G. , Gross F. 
Published: December 2008

Abstract. In male Sprague-Dawley rats the influence of salt loading (1% NaCl), deoxycorticosterone acetate (2 × 15 mg/kg/day resp. 250 mg/kg sc), corticosterone (2 × 20 mg/kg/day sc) and adrenocorticosterone (0.5 mg/kg/day tetracosactid sc) on the activity of renal kallikrein and renal renin activity was investigated.
Salt loading lowered renal kallikrein activity, deoxycorticosterone stimulated its activity and in combination they had no effect on renal kallikrein activity. The time course of kallikrein stimulation by deoxycorticosterone showed no relationship to the escape phenomenon of the kidney from the sodium retaining effect of the mineralocorticoid hormone. Reduction of endogenous mineralcorticoid hormones by adrenalectomy caused a marked reduction of urinary and renal kallikrein activity.
Corticosterone suppressed the activity of the renal kallikrein-kinin system at the same time as the reduction in urinary aldosterone excretion. Adrenocorticotrophin caused the same decrease in the activity of renal kallikrein as corticosterone. Urinary aldosterone excretion, however, was significantly stimulated. Thus, the known positive correlation between kallikrein and aldosterone was missing.
In all experiments the urinary excretion of kallikrein correlated highly with the kallikrein activity measured in renal cortical tissue. However, no correlation was found between kallikrein and urine volume or urinary excretion of sodium and potassium. In our experiments no relationship between the activity of the renin-angiotensin system and that of the renal kallikrein-kinin system was observed. Furthermore, no clear relationship was found between systemic blood pressure and the activity of the renal kallikrein-kinin system.
Comparison of methionyl human growth hormone and pituitary growth hormone on somatic growth of hypophysectomized rats
Authors: Skottner A. , Forsman A. , Löfberg E. , Thorngren K.-G. 
Published: December 2008

Abstract. In hypophysectomized male rats the biological effects of two batches of methionyl human growth hormone, Somatonorm®, (met-hGH), have been compared to those of human pituitary growth hormone, Crescormon® (hGH). The rats were treated with doses ranging from 10 mIU per day to 145 mIU per day for 10 days. The parameters studied were total weight gain, longitudinal bone growth, measured by the tetracycline method and indirect cartilage growth, measured by uptake of radioactive sulphate.
The results obtained demonstrated that Somatonorm® stimulated weight increase in a linear and dose-dependent way, similar to that seen with the native hormone. Longitudinal bone growth, measured by the tetracycline method and the growth of different cartilages, measured as uptake of radioactive sulphate, were also similar between the two hormones.
Changes in plasma thyrotrophin-releasing hormone, thyrotrophin, prolactin and thyroid hormone levels after intravenous, intranasal or rectal administration of synthetic thyrotrophin-releasing hormone in man
Authors: Mitsuma Terunori , Nogimori Tsuyoshi 
Published: December 2008

Abstract. Changes in plasma thyrotrophin-releasing hormone (TRH), thyrotrophin (TSH), prolactin and thyroid hormone levels after iv, intranasal, or rectal administration of synthetic TRH were studied in man. The plasma TRH concentration increased with all three routes, but remained at higher levels for a longer time after intranasal or rectal administration, in contrast to the rapid decrease after iv administration. Plasma TSH, prolactin and thyroid hormone levels increased significantly after intranasal or rectal administration and also remained elevated for a longer period than iv administration.
These findings suggest that TRH administered intranasally or rectally enters the blood stream and stimulates TSH, prolactin and thyroid hormone release in man.
Abnormal growth hormone levels in insulin-dependent diabetic patients under continuous subcutaneous insulin infusion and intensified conventional treatment
Authors: Arias P. , Kerner W. , de la Fuente A. , Pfeiffer E. F. 
Published: December 2008

Abstract. The present study was developed to assess the influence of prolonged blood glucose near normalization, achieved by means of continuous sc insulin infusion (CSII) or intensified conventional therapy (ICT) upon growth hormone (GH) secretion in insulin-dependent diabetes (IDD). Sixteen IDD patients (8 CSII-treated for 3–20 months and 8 under ICT) and 8 healthy control subjects were connected for 24 h to a newly developed, battery-powered glucose monitor. Diabetic patients received their usual food intake and insulin dosis. During the second hour after meals moderate exercise, walking at 1.5 km/h, was performed by all subjects. Blood samples for insulin and GH determination were taken before and 60, 120 and 180 min after meal ingestion.
Despite a similar degree of previous blood regulation, near normal glucose levels were attained only by the CSII group. Both ICT and CSII patients presented a marked postprandial hyperinsulinaemia. Abnormal GH levels were consistently registered in 4 CSII and 6 ICT patients 120 min after meal initiation. In consequence, both groups showed significantly elevated mean diurnal GH levels (controls: 1.1 ±0.3, ICT: 5.2 ± 0.9, CSII: 4.1 ± 1.1 ng/ml; P < 0.05).
According to these results, the pathologic GH secretion found in diabetic subjects is not fully normalized by tight control of blood glucose values.
Endocrinological effects of single daily ketoconazole administration in male beagle dogs
Authors: De Coster Roland , Beerens Dominiek , Dom Jef , Willemsens Gustaaf 
Published: December 2008

Abstract. Some endocrinological effects of single daily oral administration of 150 mg ketoconazole for 15 days were investigated in 4 male beagle dogs. Plasma testosterone fell markedly within 3–4 h and then progressively returned to control concentrations by 10 h after drug administration. On the other hand, plasma 17α-hydroxyprogesterone, progesterone and 17α,20α-dihydroxyprogesterone increased within 3–10 h before returning to basal values after 24 h.
Plasma LH did not rise significantly though some high individual levels were noted. Plasma cortisol and oestradiol-17α levels were not significantly modified by the treatment.
These results confirm that a high therapeutic dose of ketoconazole, given orally once a day, transiently inhibits in vivo the 17–20 lyase enzyme of the testis, without modifying basal cortisol and oestradiol-17β plasma concentrations and that enzymatic inhibition still occurs after daily treatment for up to 2 weeks but remains transient and parallels the resorption profile of the drug so that normal plasma testosterone levels are observed from 10 to 24 h after drug intake. However, permanent inhibition of androgen biosynthesis might be obtained by the administration of high doses of ketoconazole given several times a day.
Serum free T4, T3, rT3, 3,3'-diiodothyronine and 3',5'-diiodothyronine measured by ultrafiltration
Authors: Faber J. , Rogowski P. , Kirkegaard C. , Siersbæk-Nielsen K. , Friis T. 
Published: December 2008

Abstract. A simple and accurate method for estimation of the free fractions (FFT) of T4, T3, rT3, 3,3'-diiodothvronine (3,3'-T2) and 3',5'-diiodothyronine (3',5'-T2) in serum is presented. The method is based on ultrafiltration of serum pre-incubated with tracers of high specific activity, followed by purification of the ultrafiltrate on small Sephadex columns. The addition of tracer only dilutes serum negligible (about 5%) and the ultrafiltration procedure only removes about 7% of the volume of serum, thus probably not disturbing the equlibrium between the free and protein bound fraction of iodothyronine.
Progressive reduction of tracer to less than 10% of the amount usually used did not reduce the FFT of any of the iodothyronines. In contrast, addition of T4 to serum led to an increase of all FFTs except that of 3',5'-T2. These data suggest that FFT of T4, T3, rT3 and 3,3'-T2 primarily is determined by the amount of T4 present in serum and that significant amounts of these iodothyronines are bound to TBG, whereas 3',5'-T2 possibly primarily is bound to albumin.
The median FFT of T4, T3, rT3, 3,3'-T2 and 3',5'-T2 in serum from euthyroid subjects (n = 38) was: 0.030, 0.29, 0.14, 1.10 and 1.07%, respectively. The corresponding median free concentrations in pmol/l were: 30, 4.79, 0.59, 0.44 and 0.77, respectively.
Pregnant women in 3rd trimester had normal levels of free T4, free T3 and free rT3, wheras the median free 3,3'-T2 was reduced in contrast to elevated median free 3',5'-T2.
Using the present method free T4 and free T3 discriminated almost completely hyper- and hypothyroid patients from controls, whereas some overlap to normal range was found concerning free rT3, free 3,3'-T2 and free 3',5'-T2.
Patients with liver cirrhosis or chronic renal failure (CRF) had profound changes in total serum concentrations of all iodothvronines studied, possibly due to the somatic disease. Despite this, almost all had unchanged free T4 and free T3 levels indicative of euthyroidism. The median free rT3 and free 3',5'-T2 were elevated in cirrhosis but unchanged in CRF, whereas median 3,3'-T2 was unchanged in both groups.
Danazol and prolactin status in patients with endometriosis
Authors: Wallace A. M. , Lees D. A. R. , Roberts A. D. G. , Gray C. E. , McLaren E. H. , Low R. A. L. 
Published: December 2008

Abstract. A group of 55 women with endometriosis was studied before and during danazol therapy. An unexpectedly high proportion (36%) had a raised serum prolactin level before treatment which was reduced after 50 days of danazol (before treatment 783 ± 333 mU/l; on danazol 243 ± 113 mU/l, P < 0.001). In contrast patients with normal serum prolactin levels showed no significant drop on danazol therapy. In all patients serum oestradiol was significantly reduced during treatment (before treatment 449 ± 188 pmol/l; on danazol 207 ± 117 pmol/l, P < 0.001). In one patient with hyperprolactinaemia danazol reduced both basal and stimulated prolactin levels, whereas in 5 women with normal prolactin levels we could detect no gross alteration in metoclopramide or TRH stimulated prolactin levels associated with danazol therapy.
The possibility that normalisation of raised prolactin levels may be secondary to reduced oestrogens and that patients with endometriosis have an increased sensitivity to oestrogen-induced prolactin secretion is discussed.
Tonic effect of endogenous TSH on the in vitro thyroid cAMP response to TSH
Authors: Ikeda Hitoshi , Uchimura Hidemasa , Nagataki Shigenobu 
Published: December 2008

Abstract. The present study was undertaken to compare the effects of 3,5,3'-triiodothyronine (T3) alone and T3 plus bovine thyrotrophin (bTSH) given chronically in vivo on the TSH-stimulated cyclic adenosine 3',5'-monophosphate (cAMP) production in a mouse thyroid in vitro. Mice were given T3 (5 μg/ml) in drinking water for 4 days. The thyroid cAMP concentrations after an incubation with 10 mU/ml of TSH for 10 min were decreased by 50% in T3-treated mice as compared to the control. In the second experiment, mice were given T3 alone or T3 plus 0.5 mU of bTSH ip daily for 4 days. The combined treatment with T3 and TSH partially restored the reduction of cAMP response to TSH that was induced by T3 alone. In the third experiment, mice were given T3 alone for 7 days, or T3 for 7 days plus TSH for the last 3 days. The reduced cAMP response to TSH induced by T3 alone was again partially restored by the concomitant treatment with TSH.
These results indicate 1) that the capacity of the thyroid cAMP to respond to TSH is regulated, at least in part, by a trophic effect of endogenous TSH and 2) that the impaired capacity caused by a loss of tonic effect of endogenous TSH is reversible.
Thyroid hormone maintains normal circadian rhythm of blood corticosterone levels in the rat by restoring the release and synthesis of ACTH after thyroidectomy
Authors: Murakami Noboru , Hayafuji Chieko , Takahashi Kiyohisa 
Published: December 2008

Abstract. The role of thyroid hormone in maintenance of the circadian adrenocortical rhythm was studied in the rat. The amplitude of the circadian rhythm of blood corticosterone levels gradually decreased with time after thyroidectomy, and by 5 weeks the rhythm disappeared. However, the circadian peak elevation constantly occurred just before the onset of the dark period until 4 weeks. Three weeks after thyroidectomy, daily overall treatment with thyroxine (T4) or 3,5,3'-triiodothyronine (T3) completely restored the amplitude of the circadian adrenocortical rhythm to the previous level within 2 weeks. Thyroidectomy did not affect the circadian rhythm in water intake.
However, thyroidectomy resulted in a loss of significant difference of plasma adrenocorticotrophin (ACTH) levels between the morning and the evening, by decreasing the evening levels. Similarly, pituitary ACTH content was decreased by thyroidectomy. Replacement of T4 completely restored the decreased ACTH levels to the previous ones.
These results suggest that thyroid hormone plays an important role in maintenance of the normal amplitude in circadian adrenocortical rhythm in the rat, by affecting ACTH synthesis.
Effect of somatostatin on growth hormone and prolactin response to dermorphin in man
Authors: Uberti E. C. degli , Trasforini G. , Salvadori S. , Margutti A. , Teodori V. , Rotola C. , Tomatis R. , Pansini R. 
Published: December 2008

Abstract. The effects of iv somatostatin (somatotrophin release inhibiting factor (SRIF)) on growth hormone (GH) and prolactin (Prl) response to dermorphin (D) were tested in 6 healthy men. In all subjects D induced a significant increase in GH and Prl levels, as expected. SRIF completely blocked the GH-releasing activity of D, whereas it only reduced the Prl-releasing activity.
The results confirm that D is a potent stimulant for GH and Prl release in man, and furthermore demonstrate that the action of D on GH secretion can be completely overridden by SRIF.
Effect of naloxone on oxytocin-induced cortisol decrease in normal men
Authors: Coiro V. , Chiodera P. , Rossi G. , Volpi R. , Salvi M. , Camellini L. , Roti E. 
Published: December 2008

Abstract. iv administration of oxytocin decreases plasma ACTH-cortisol levels in normal men. In contrast, naloxone, a specific opioid antagonist, stimulates cortisol release, suggesting that opioid peptides exert an inhibitory control on ACTH-cortisol secretion.
The present study was carried out in an attempt to determine whether an opioid pathway mediates oxytocin action; therefore, we evaluated the effect of naloxone on the decrease of cortisol induced by oxytocin.
Six normal men were treated iv with oxytocin (2 IU as a bolus), naloxone (4 mg as a bolus plus 10 mg infused for 2 h) or a combination of the 2 drugs. Plasma cortisol levels were determined in samples taken before and 2 h after drug treatment. As expected, administration of oxytocin significantly decreased cortisol secretion, while naloxone had a stimulatory effect on plasma cortisol levels. When oxytocin injection was followed by administration of naloxone, cortisol levels remained unchanged; thus, naloxone abolished a cortisol decrement in response to oxytocin.
These findings show that in man oxytocin requires an active opioid system in order to produce its inhibitory action on ACTH-cortisol secretion, suggesting that this effect of oxytocin could be mediated by an opioid pathway.
Components of the rat conceptus that account for prolactin inhibition
Authors: Yogev L. , Terkel J. 
Published: December 2008

Abstract. The secretions from developed concepti in the rat appear to inhibit both the rhythmic nocturnal secretion of prolactin (Prl) during the second half of pregnancy and the neurally mediated Prl release in response to suckling stimulation. In order to identify the parts of the concepti capable of inhibiting Prl secretion, the components of the concepti were systematically removed and their effect on plasma Prl levels was examined.
In the first experiment, female rats which were simultaneously pregnant and lactating were tested for Prl secretion in response to suckling stimulation after one of the following treatments: 1) removal of the foetuses only, 2) removal of the foetuses and trophoblasts, 3) removal of the complete concepti. In the second experiment, pregnant rats were tested for the presence of nocturnal Prl surges after either removal of the foetuses and trophoblasts or removal of the entire concepti.
The results indicate that after removal of the foetuses alone, the inhibition of Prl secretion remains. Following removal of both the foetus and the trophoblast, leaving the decidua in situ with a supplementary progesterone implant, the decidua still retain a partial capacity to inhibit Prl secretion in response to suckling stimulation, while their inhibitory effect on the nocturnal Prl surges was very minute. Degeneration of the decidua occurred following the removal of the trophoblast, when no exogenous progesterone was supplied. The deterioration of the decidua or total removal of the concepti eliminates the entire inhibition of Prl secretion, both on the nocturnal surges as well as in response to suckling stimulation.
Thus, it appears that after mid-pregnancy the trophoblast cell secretes a substance that both inhibits Prl secretion and maintains the corpus luteum, whereas the decidua at the same time secretes a substance that has a partial capacity to inhibit Prl secretion in response to suckling stimulation.
Nuclear reverse T3 binding sites: an artefact of isolation?
Authors: Hartong R. , Wiersinga W. M. 
Published: December 2008

Abstract. Binding of [125I]rT3 to rat liver nuclear extracts prepared in 0.25 m sucrose could be abolished by a prior wash of the nuclei with 2.4 m sucrose. Analysis of mixtures containing [125I]rT3 and nuclear extracts (0.25 m sucrose) showed that after incubation for 2 h at 22°C, degradation of rT3 into 3,3'-T2 and I- had taken place. It appears that the presence of 125I- in these mixtures can account for the previously observed 'binding' of [125I]rT3 to these nuclear extracts.
Further characterization of the deiodination process in nuclear extracts showed: 1) inactivation by heating, 2) production of equimolar amounts of I- and 3,3'-T2, 3) stimulation by sulfhydryl compounds and inhibition by propylthiouracil in a fashion similar to the microsomal iodothyronine 5'-deiodinase (ping-pong mechanism).
We conclude that the observed deiodination of rT3 in hepatic nuclear extracts is of enzymatic nature, due to contamination of the nuclear preparation by microsomal iodothyronine 5'-deiodinase. However, since the nuclei are prepared in the presence of the non-ionic detergent Triton X-100, a nucleus associated deiodinase activity cannot be totally excluded.
Oestradiol binding to nuclei of anterior pituitary cells of the ram
Authors: Thieulant Marie-Lise , Pelletier Jean 
Published: December 2008

Abstract. The methodology to fully characterise nuclear receptor for oestradiol-17β (E2) in the ram pituitary has been investigated. Purified nuclei, clean under the electron microscope, were obtained from 2.4 m sucrose ultracentrifugation and were extracted for 2 h at 0°C with 0.6 m NaCl. After centrifugation, the supernatant was incubated with [3H]E2 with or without a 100-fold excess of unlabelled E2.
The main results were:
the specific binding was maximum at 20°C in 2–3 h and remained constant up to 19 h without significant metabolism; an incubation temperature of 25°C reduces the binding, while at 0°C maximum binding was attained at a much slower rate; the binding was linearly related to the dose of nuclear proteins; the binding was not affected by DNase and RNase but was suppressed by trypsin, pronase or a temperature of 56°C; binding was specific for oestrogens; preincubation of cytosol with [3H]E2 and then coincubation with nuclei showed an uptake of the [3H]E2 receptor complex by nuclei; such a transfer was inhibited if cytosol was previously heated; after a prelabelled cytosol-nuclei coincubation, a specific binding peak was found in the nuclear extract submitted to sucrose gradient sedimentation (4.1S); in vivo injection of 100 μg E2 resulted in a sharp increase in nuclear receptor numbers 30 and 60 min later, with a concomitant drop in cytosolic receptor numbers.
These results indicate that E2 can bind to pituitary nuclei in the ram.