bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stroma of human benign prostatic hyperplasia: preferential tissue for androgen metabolism and oestrogen binding
Authors: Krieg M. , Klötzl G. , Kaufmann J. , Voigt K. D. 
Published: December 2008

Abstract.
Because of the well known stromal-epithelial interaction of various urogenital organs, it was of interest to compare quantitatively steroid metabolism and binding in epithelium (E) and stroma (S) of the human benign prostatic hyperplasia (BPH).
Testosterone 5α-reductase activity was determined by thin-layer chromatography and androgen as well as oestrogen binding sites by a charcoal adsorption technique after a steroid incubation period of 18 h at 0°C, using methyltrienolone (R1881) and oestradiol-17β as tritiated ligands and unlabelled R1881 and diethylstilboestrol as the respective competitors.
The main results were as follows: (1) using biochemical markers (acid phosphatase, hydroxyproline), an on average 17% contamination of E by S and 6% of S by E was found, (2) the molar optimum of NADPH for the enzyme reaction was nearly identical in E and S, ranging between 1 and 0.1 mm, (3) the apparent Michaelis constant (Km) of 5α-reductase was in both fractions identical, the mean being 0.15 (μm, (4) the maximal rate of 5α-reductase activity (pmol 5α-reduced metabolites · mg protein−1 · 1 h−1) was 161 ± 28 (sem; n = 20), 66 ± 4.6 and 148 ± 6.6 in S, E and whole tissue fraction of BPH, respectively. In two normal prostates the means were: 88, 53 and 73, respectively, (5) the androgen binding sites were evenly distributed between the cytosol of E and S, while measurable oestrogen binding sites were found in 42% of the analyzed S but only in 5% of analyzed E.
In conclusion: the 2.4 times higher 5·-reductase activity in S compared to E of the BPH is responsible for the about 2 to 2.5 times higher activity in the whole tissue fraction of BPH if compared with the normal prostate. Furthermore, due to our preliminary binding studies, oestrogens might play an important role in the S fraction of BPH.
Dose related effects of betamethasone on iodothyronines and thyroid hormone-binding proteins in serum
Authors: Gamstedt Anders , Järnerot Gunnar , Kågedal Bertil 
Published: December 2008

Abstract.
Earlier studies of the effect of glucocorticoids on thyroid function tests have given different results. This may be due to the fact that varying corticosteroid doses have been used. The present study examines four groups of healthy volunteers, who were given betamethasone in increasing doses (1.5, 3.0, 4.5 and 6.0 mg daily) for 5 days. Definite dose-response relations were found for serum T4 and T3 while no clear-cut dose-response pattern was found for rT3. The results obtained explain previous variable results. Oral corticosteroids also affected the concentrations of the thyroid hormone-binding proteins but no clear-cut dose-response relation were observed.
Effects of octanoate and ketone bodies on the structure and function of isolated pancreatic islets in tissue culture
Authors: Borg L. A. H. 
Published: December 2008

Abstract.
To study the effects of fatty acids and ketone bodies on both insulin release and lasting changes in ultrastructure and function of the pancreatic B-cell, isolated mouse islets were cultured for one week in the presence of either octanoate, acetoacetate or 3-hydroxybutyrate. The glucose concentration of the unsupplemented culture medium was 3.3 mmol/l and islets cultured in this medium were used as controls. It was found that octanoate stimulated insulin accumulation in the culture medium, decreased the islet insulin content and also effected a degranulation of the islet B-cells. Although there was no significant change in the total mitochondrial volume of the octanoate cultured islets, the activity of the mitochondrial marker enzyme L-3-hydroxyacyl-CoA-dehydrogenase was decreased. In short-term incubations performed after culture with octanoate, there was an increased rate of islet protein biosynthesis, which seemed to be independent of a glucose challenge. After culture of islets with acetoacetate, morphometrical measurements indicated an increased islet cell size, but there appeared to be no further effects of this ketone body on the islet ultrastructure or function. 3-Hydroxybutyrate, however, increased both the insulin accumulation in the culture medium and the insulin content of the cultured islets. Apparently, the β-granule content of the islets exposed to 3-hydroxybutyrate also increased. Furthermore, there was a reduction in the total mitochondrial volume of the 3-hydroxybutyrate cultured islets. In addition, the activity of L-3-hydroxyacyl-CoA-dehydrogenase was reduced, whereas islet glucose oxidation was markedly increased. In conclusion, therefore 3-hydroxybutyrate greatly resembled glucose in its effects on the islet B-cells.
Increased thyrotrophin and prolactin secretion induced by domperidone in hypothyroid subjects
Authors: Massara F. , Camanni F. , Amoroso A. , Molinatti G. M. , Müller E. E. 
Published: December 2008

Abstract.
The thyrotrophin (TSH) and prolactin (Prl) releasing effects of domperidone, a recently developed antidopaminergic drug which does not cross the blood-brain barrier, were investigated in 8 women affected by primary hypothyroidism, and were compared to those elicited by another antidopaminergic drug, sulpiride. Domperidone (4 mg iv) induced a clear-cut and sustained rise in both plasma TSH and Prl, with peak levels occurring 15 and 30 min post-injection, respectively. The increments in plasma Prl after domperidone were significantly higher than those in plasma TSH. The TSH and Prl responses induced by domperidone were almost superimposable to those provoked in the same subjects by sulpiride (100 mg im). In view of the inability of domperidone to penetrate into the central nervous system (CNS), these findings imply a 'peripheral' site(s) of action (i.e., anterior pituitary and/or median eminence) for the effect of antidopaminergic drugs on TSH secretion, and, re-iterate the notion that the same 'peripheral' sites are involved in the Prl-releasing effect of these compounds.
Increase in thyroxine-binding globulin (TBG) in lysinuric protein intolerance
Authors: Lamberg B.-A. , Perheentupa J. , Rajantie J. , Simell O. , Saarinen P. , Ebeling P. , Welin M.-G. 
Published: December 2008

Abstract.
The common occurrence of increased serum PBI concentration in patients with lysinuric protein intolerance (LPI) was elucidated by further studies. The reason was found to be an increase in the concentration of thyroid binding globulin (TBG), concomitantly with an increase in the binding capacity of TBG. The concentrations of serum thyroxine and triiodothyronine were elevated, whereas the free thyroxine index remained normal. The free triiodothyronine index was slightly increased. The binding capacity of thyroid hormone binding pre-albumin (TBPA) was significantly decreased. The concentrations of reverse triiodothyronine (3,3',5'-T3) and of 3,3'-diiodothyronine were normal. In all patients serum lactic acid dehydrogenase activities and ferritin concentrations were elevated.
The reason for the almost constant increase in TBG remains obscure. It may be related to the primary disorder of LPI, a defect in diaminoacid transport.
Effect of meclastine, an H1-antihistamine, on plasma ACTH in adrenal insufficiency
Authors: Allolio B. , Winkelmann W. , Hipp F. X. 
Published: December 2008

Abstract.
In order to evaluate the possible role of endogenous histamine in ACTH secretion we investigated the effect of the H1 antagonist meclastine on plasma ACTH in patients with ACTH hypersecretion. Seven patients with primary adrenal insufficiency (group 1) and 5 patients with ACTH dependent Cushing's syndrome (group 2) were given an iv infusion of meclastine (4.8 mg/90 min). In patients of group 2 plasma ACTH was unaffected by meclastine infusion. However, in patients of group 1 with intact steroid feedback meclastine was followed by a significant drop in plasma ACTH as compared with ACTH levels after saline infusion (46.0 ± 4.6% vs 85.0 ± 7.0%, P < 0.01). These results suggest that histamine is involved in the control of ACTH secretion, possibly by stimulation of CRF release.
Studies on the biological and immunological properties of human follitropin: profiles of two international reference preparations and of an aqueous extract of pituitary glands after electrofocusing
Authors: Zaidi A. A. , Robertson D. M. , Diczfalusy E. 
Published: December 2008

Abstract.
Two international reference preparations, the First International Reference Preparation of Human Pituitary Gonadotrophins (FSH and LH/ICSH) for Bioassay (identified hereafter by its code no.: 69/104) and the First International Standard of Urinary FSH and LH (ICSH) for Bioassay (hereafter: hMG 1st IS) and an aqueous extract of human pituitary glands (hPE) were fractionated in triplicate by isoelectric focusing on sucrose density gradient (Ampholine, pH range 2.5–10.0). The FSH activity was monitored in each fraction by an in vitro bioassay, a radioimmunoassay and a receptor binding assay. Unfractionated 69/104 was used as standard in each assay system.
Compared with the hPE, the activity profiles of the 69/104 and hMG reference preparations were spread over a significantly wider pH range; the biological activity eluted in the pH range of 3.5–5.0 was of the order of 90% for hPE, 72% for 69/104 and less than 60% for hMG.
Major variations in biological to immunological (B/I) and biological to receptor binding (B/R) activity ratios were observed in the individual electrofocusing fractions. The B/I ratios ranged from 0.8 to 2.2 (69/104), 1.0–5.7 (hMG) and 1.3–6.0 (hPE), respectively. The variation in the corresponding B/R ratios was: 0.5–1.7 (69/104), 0.58–4.0 (hMG) and 0.55–1.5 (hPE). When equal aliquots from each of the electrofocusing fractions were combined and this 're-constituted' pool was compared with the starting material, significant differences were observed in the B/I ratios: 1.63 instead of 1.0 (69/104), 2.58 vs 2.34 (hMG) and 2.72 vs 1.32 (hPE). There was no significant change in the mean B/R ratios before and after electrofocusing: 1.0 vs 1.02 (69/104), 1.09 vs 1.02 (hMG) and 1.05 vs 1.04 (hPE).
The mean recovery of biological activity in each of the three reconstituted pools of the three preparations was 97% for 69/104, 88% for hMG and 98% for hPE, and the corresponding recoveries of receptor binding activities were 95%, 94% and 98%, respectively. In contrast, the mean recovery of immunological reactivity was only 55% (69/104), 80% (hMG) and 47% (hPE), respectively.
The reduction in the immunological reactivity of the 69/104 preparation without any apparent loss of biological or receptor binding activities following electrofocusing indicates that its immunoreactivity is unstable under mild experimental conditions, which do not influence its biological and receptor binding activities. Hence, whereas this preparation might possibly be suitable as a standard for in vitro bioassays and receptor binding assays, it is unsuitable as a standard for the radioimmunoassay of hFSH.
Force development and metabolism in skeletal muscle of euthyroid and hypothyroid rats
Authors: Everts M. E. , van Hardeveld C. , Keurs H. E. D. J. Ter , Kassenaar A. A. H. 
Published: December 2008

Abstract.
The effects of thyroid hormone depletion on skeletal muscle metabolism in relation to force development were studied. For this purpose, the triceps surae muscles were perfused and stimulated at 5 Hz. The basal oxygen consumption of the skeletal muscle preparation was 50% lower in hypothyroid rats as compared with euthyroid rats.
The results show that:
1. Active force development was the same in euthyroid and hypothyroid rats during 30 min of stimulation.
2. The increase in oxygen consumption during contraction was twice as high in the euthyroid group compared with the hypothyroid group.
3. Lactate release and glucose consumption were considerably higher in the euthyroid group than in the hypothyroid group during the last 15 min of stimulation. The data show that force development is not impaired in hypothyroid rats but, on the contrary, indicate that the contraction process proceeds more economically in hypothyroid rats than in euthyroid rats.
Potentiation of prostaglandin E2-induced release of LH by the prostaglandin analogue, 7-oxa-13-prostynoic acid
Authors: Warberg Jørgen 
Published: December 2008

Abstract.
The prostaglandin (PG) analogue 7-oxa-13-prostynoic acid (7-OPA) was infused into a lateral ventricle of the brain of adult male rats and the effect of the analogue on a subsequent stimulation of LH release by intraventricular infusion of PG's was determined. Pre-treatment of the animals with 44–132 μg of 7-OPA potentiated the stimulatory effect of 2 μg PGE2 on the release of LH but the analogue alone had no effect on the hormone secretion. The minimal effective dose of PGE2 was determined to be within the range 0.01–0.05 μg and it was found that priming with 132 μg of 7-OPA caused a formerly sub-threshold dose (0.01 μg) of PGE2 to become an effective stimulus for the release of LH. In contrast to its potentiating effect on PGE2-induced LH release 7-OPA did not alter the stimulatory action of PGF2α (2 μg) on the secretion of LH. 7-OPA had no effect on LRH-induced release of LH indicating that the PG analogue acts at a suprapituitary site to enhance PGE2-induced LH release. The potentiating effect of 7-OPA may be exerted at a binding site for PGE2 in the brain and the results suggest the existence of a different binding site for PGF2α. The possibility also exists that 7-OPA inhibit metabolic inactivation of PGE2.
Patterns of spontaneous LH release in normo- and hyperprolactinaemic women
Authors: Buckman Maire T. , Peake Glenn T. , Srivastava Laxima , Morris Josephine , David Barry , Shah Bharat 
Published: December 2008

Abstract.
Hyperprolactinaemia may be associated with functional amenorrhoea. In order to evaluate the possible role of abnormal spontaneous LH secretion in hyperprolactinaemic amenorrhoeic women, plasma LH was measured at 15 min intervals for 300 min in 12 normal women during the early follicular phase of the menstrual cycle and compared to that observed in 11 hyperprolactinaemic amenorrhoeic subjects. Mean plasma prolactin was 9.1 ± 3.6 ng/ml (x̄ ± sem) in the euprolactinaemic and 168 ± 32 ng/ml in the hyperprolactinaemic group. Sex steroids including oestrone, oestradiol, progesterone and 17-hydroxyprogesterone were similar in the 2 groups. Mean plasma LH levels over the 300 min sampling period were 9.4 ± 1.6 mIU/ml in the normal subjects and 7.5 ± 1.0 mIU/ml in the hyperprolactinaemic patients (P>0.10). Every normal woman exhibited at least one LH spike in excess of 10 mIU/ml. Five hyperprolactinaemic patients failed to exhibit any LH spikes above 10 mIU/ml (P < 0.02 compared to controls). Thus, hyperprolactinaemia was associated with an absence of LH spike activity in 45% of patients studied and this abnormality may play an aetiologic role in the hypogonadism observed in these subjects; in those hyperprolactinaemic subjects with pulsatile LH secretion, however, other explanations for their amenorrhoea should be considered.
Dynamic evaluation of prolactin secretion with sulpiride and thyrotrophin releasing hormone in amenorrhoeic and normally menstruating women
Authors: D'Agata R. , Aliffi A. , Gulizia S. , Vicari E. 
Published: December 2008

Abstract.
Sulpiride and TRH were used to evaluate the dynamics of prolactin (Prl) release in normoprolactinaemic, amenorrhoeic and normally menstruating women. The two tests were performed in a randomized order with an interval of 2—3 days. In the normal women the first test was carried out between days 2 and 4 of their cycle. Basal values during the two tests were not statistically different (9.6 ± 1.2 se vs. 10.7 ± 1.4 ng/ml in amenorrhoeic women with sulpiride and 11.3 ± 1.4 vs. 12.4 ± 1.7 in amenorrhoeic women during the TRH test). The two tests were performed while the subjects of the two groups had identical serum oestrogen concentrations. The Prl response following TRH administration was similar in both groups (Δmax [unk]49.5 ± 12.5 se and 49.4 ± 8.5 se in normal and amenorrhoeic women, respectively). In contrast, when release by sulpiride administration was studied the normal women had greater Prl release (Δmax [unk] 169.9 ± 18.2 se) than amenorrhoeic women (Δmax [unk] 99.8 ± 9.4). Either the different oestrogen status (lower in amenorrhoeic women than in menstruating women) or the hypothalamic pituitary dysfunction likely to be responsible for the amenorrhoea in our patients, may explain the lower Prl release observed after sulpiride in subjects with amenorrhoea.
The effects of water deprivation and water loading during treatment with 1-deamino-8-D-arginine vasopressin in central diabetes insipidus in childhood
Authors: Becker Dorothy J. , Foley Thomas P. 
Published: December 2008

Abstract.
Nine children aged 72/12 to 179/12 years with central diabetes insipidus were subjected to water deprivation and water loading during treatment with 1-deamino-8-D-arginine vasopressin (DDVAP). Urine output remained unchanged despite the large differences in water intake. Serum osmolarity was not significantly affected by water deprivation. However, there was a marked decrease in serum osmolarity during water loading. This was not accompanied by any symptoms of haemodilution. Thus patients apparently tolerate large variations in fluid intake during therapy with DDVAP.
Syndrome of'inappropriate secretion of thyroid-stimulating hormone' by partial target organ resistance to thyroid hormones
Authors: De Diego J. Salmerón , Rodriguez C. Alonso , Orlando A. Salazar , Cervigon P. Sanchez Garcia , Mutazzi E. Caviola , Mateos J. M. Palacios 
Published: December 2008

Abstract.
A 74 year old woman was found to have elevated serum thyroid-stimulating hormone (TSH) levels and elevated serum thyroid hormone levels, with clinical euthyroidism. There was no evidence of a pituitary tumour. TSH levels increased substantially during methimazole therapy. Administration of dexamethasone was followed by a prompt fall in serum TSH levels. Triiodothyronine (T3) was administered over a period of 20 days in doses from 25 μg to as much as 100 μg daily causing a rise in serum T3 above 700 ng/100 ml, a decline of T4 and a blunting of the response to thyrotrophinreleasing hormone (TRH), with normal metabolic responses (pulse rate, photomotogram, cholesterol).
These results suggest that the patient's disorder is due to partial target organ resistance to thyroid hormones.
Disappearance of insulin in man: variation with the plasma insulin level
Authors: Tranberg Karl-Göran , Hagander Per , Thorell Jan 
Published: December 2008

Abstract.
Clearance rates of unlabelled insulin were studied in 45 unanaesthetized non-diabetic humans. The clearance rate, as well as the pancreatic secretion rate, of endogenous insulin was estimated from steady-state concentrations in portal and arterial blood. The clearance rate of exogenous insulin was determined after brief intraportal infusion.
In the basal fasting state, the endogenous plasma insulin level varied as closely with the clearance of endogenous insulin as with the rate of pancreatic secretion. During elevation of insulin by glucose infusion, it varied predominantly with the rate of insulin secretion. Clearance of exogenous insulin did not vary with the pre-test endogenous insulin level. The clearance of endogenous insulin increased from 11 ml · min−1 · kg−1 in the basal fasting state to 17 ml · min−1 · kg−1 during glucose infusion. Clearance of exogenous insulin fell progressively with increasing dose, from 35 (8 mU/kg) to 14 (43 mU/kg) ml · min−1 · kg−1 at normoglycaemia and from 23 (8 mU/kg) to 17 (34 mU/kg) ml · min−1 · kg−1 at hyperglycaemia. The clearance of endogenous insulin was lower than that of exogenous insulin at normoglycaemia, but of similar size during glucose infusion.
It is concluded that variation in clearance rate is partly responsible for variation in plasma insulin concentration, particularly in the basal fasting state, and that the clearance rate is lower in the basal state than otherwise. To some extent, the low clearance values for endogenous insulin in the basal state may reflect poor specificity of the insulin radioimmunoassay.
Plasma cyclic nucleotides and plasma catecholamines before and after prolonged treatment with clonidine in hypertensive patients
Authors: Manhem Per , Heding Lise , Malmquist Jörgen , Hökfelt Bernt 
Published: December 2008

Abstract.
The effect of standing and physical exercise on catecholamines and cyclic nucleotides in plasma was measured in 8 patients with essential hypertension under standardized conditions before and after prolonged treatment with clonidine.
Before clonidine medication noradrenaline, adrenaline and cyclic AMP (cAMP) increased in response to standing and bicycling for 20 min. No significant correlation was found between their absolute levels nor was the increase in cAMP following exercise correlated to the increase in noradrenaline. Standing and physical exercise were without effect on cyclic GMP (cGMP).
Clonidine reduced the plasma noradrenaline concentration in supine position and the noradrenaline and the adrenaline response to standing and exercise. Plasma cAMP was uneffected by clonidine under basal conditions but the response to exercise was slightly reduced initially. During clonidine there was a positive correlation between the plasma levels of cAMP and noradrenaline following work. Clonidine produced an increase in plasma cGMP in supine position, immediately prior to bicycling and after 5 min of exercise.
Growth hormone and prolactin secretion in liver cirrhosis: evidence for dopaminergic dysfunction
Authors: Borzio Mauro , Caldara Roberto , Ferrari Carlo , Barbieri Cristiano , Borzio Franco , Romussi Mario 
Published: December 2008

Abstract.
Increased serum growth hormone (GH) and prolactin (Prl) levels and abnormal responses to some stimuli have been reported in patients with chronic liver disease. Serum GH and Prl concentrations were measured in 11 cirrhotic patients and in sex and age matched healthy controls in basal conditions and after administration of L-dopa alone (500 mg), and L-dopa (100 mg) with carbidopa (35 mg) following pre-treatment with carbidopa (50 mg every 6 h for one day), a regimen which results in selective activation of brain dopaminergic pathways. Basal GH and Prl levels were significantly higher in cirrhotics than in controls; serum GH did not increase significantly and serum Prl was subnormally inhibited in patients after both tests. A patient with clearcut hyperprolactinaemia unresponsive to dopaminergic stimulation showed normal basal Prl levels and suppression by L-dopa following clinical improvement, while her elevated GH levels remained unchanged and did not increase after L-dopa.
These data confirm the existence of abnormalities in the regulation of GH and Prl release in liver cirrhosis and suggest that dopaminergic dysfunction may be responsible. The subnormal Prl suppression induced by L-dopa, which stimulates both brain and peripheral dopaminergic receptors, suggests that dopaminergic dysfunction is not confined to the central nervous system in liver cirrhosis. It appears that serum Prl concentration may be of value in monitoring decompensated liver disease and that abnormalities of Prl secretion are reversible with clinical improvement.