bluuebunny/crossref_metadata_2025_split huggingface dataset:
A HIGH SENSITIVITY IMMUNOCHEMILUMINOMETRIC ASSAY FOR HUMAN THYROTROPHIN
Authors: WEEKS I. , STURGESS MARIA , SIDDLE K. , JONES M. K. , WOODHEAD J. S. 
Published: March 2008

SUMMARYA. two‐site immunochemiluminometric assay (ICMA) has been developed for the measurement of human thyrotrophin (TSH). The procedure involves reaction of serum samples with monoclonal antibodies to TSH which have been labelled with a chemiluminescent acridinium ester followed by reaction with solid‐phase polyclonal antibodies to TSH. The total reaction time is 2 h and bound labelled antibody is quantified luminometrically. The assay has an absolute sensitivity of 0.004 mU/1 and a linear dose‐response range up to 60 mU/1. Circulating TSH concentrations in 84 normal subjects were in the range 0.4 to 4.0 mU/1 and in 16 hyperthyroid patients were less than 0.03 mU/1. This assay should thus prove useful as a first line test of thyroid function.
EFFECT OF METOCLOPRAMIDE ON PLASMA VASOPRESSIN IN MAN
Authors: NOMURA K. , KURIMOTO F. , DEMURA H. , SAKURAI H. , NOMURA T. , ZIBIKI K. , NARUSE M. , KANAI N. , SHIZUME K. 
Published: March 2008

SUMMARYThe effect of metoclopramide, a dopamine blocker, on arginine vasopressin (AVP) secretion was investigated in normal males. After a bolus injection of metoclopramide (10 mg), all subjects (n= 7) demonstrated an increase of 80‐3% (from 0.71 ±0.12 (Mean ± S.E.) to 1.28 ± 0.24 pg/ml, P± 0005) in plasma AVP at 15 min. In controls (n = 7) plasma AVP levels did not change after saline injection (2 ml). Because plasma osmolality and blood pressure did not change, the elevation of plasma AVP levels induced by treatment with metoclopramide may be due to its central effect as a dopamine inhibitor. Although plasma AVP levels increased again at 90 and 120 min after a bolus injection of metoclopramide, accompanying falls in blood pressure (4‐5%) make the interpretation concerning the contribution of dopamine to AVP secretion in a late phase uncertain. In summary, plasma AVP levels were shown to be significantly increased by a metoclopramide bolus, suggesting that AVP secretion is under tonic inhibition by dopamine.
THE EFFECTS OF BROMOCRIPTINE ON THE SEXUAL BEHAVIOUR OF HYPERPROLACTINAEMIC MAN: A CONTROLLED CASE STUDY
Authors: BANCROFT J. , O'CARROLL R. , MCNEILLY A. , SHAW R. W. 
Published: March 2008

SUMMARYA 44‐year old man presented with loss of sexual interest and erectile failure and together with his wife was treated successfully with sexual counselling. He was subsequently found to have been hyperprolactinaemic before and after sex therapy. Comparison of bromocriptine with placebo in two double blind studies showed a modest increase in sexual interest when his prolactin levels fell to normal. In this case, the principal effect of hyperprolactinaemia was on sexual interest. His main problems, erectile impotence and decline in sexual activity, resulted from his and his wife's psychological reaction to this modest hormonal effect. Hyperprolactinaemia appears to have a similar effect to testosterone deficiency in men.
EVIDENCE FOR AN EFFECT OF ANTITHYROID DRUGS ON THE NATURAL HISTORY OF GRAVES' DISEASE
Authors: WEETMAN A. P. , McGREGOR A. M. , HALL R. 
Published: March 2008

SUMMARYIn the United Kingdom, about half the patients with Graves' disease who are given antithyroid drugs are still in remission one year after treatment is stopped. The most widely held view is that such remission rates are due only to the biochemical effects of the drugs, the disease either spontaneously remitting or abating when the immune system is no longer subject to the stimulatory effects of excessive thyroid hormone. We review here the accumulating evidence against both of these alternatives. In contrast, there is now a large body of work which shows that thyrotrophin receptor antibody levels, central to the aetiology of Graves' hyperthyroidism, fall during antithyroid treatment and that remission may be related to this fall in a fashion which is dependent on the dose and duration of treatment. This immunosuppressive effect is supported by experimental data and on the basis of these results we propose that antithyroid drugs may modify the natural history of Graves' disease and contribute to the remission which occurs in a proportion of treated patients.
POTENTIAL USES OF HUMAN PANCREATIC GROWTH HORMONE‐RELEASING FACTOR 1‐44 AMIDE
Authors: BELCHETZ P. E. , WELDON S. F. , DAVIS J. C. , DIVER M. J. , SMITH C. S. , HARRIS F. 
Published: March 2008

SUMMARYA family of growth hormone releasing peptides have been isolated and characterized from human pancreatic islet cell tumours. We have compared the growth hormone release in normal volunteers and patients with various hypothalamo‐pituitary disorders, following direct stimulation of the pituitary using 50μg of the most potent homologue, hp GRF 1‐44 amide i.v. with that following indirect stimulation using oral clonidine 0‐15 mg/m2, which depends on intact hypothalamic mechanisms. These tests both produced a wide variation in GH response in normal volunteers, considerable GH release following hp GRF 1^44 amide but little after clonidine in idiopathic GH deficiency, and indistinguishable, negligible responses in patients with craniopharyngiomas and pituitary tumours associated with GH deficiency. Two untreated acromegalics showed GH increments in the normal range despite elevated basal levels. It is concluded that hp GRF 1‐44 amide is of limited diagnostic value by itself, but may be of considerable therapeutic use in patients with idiopathic GH deficiency.
THYROGLOBULIN SECRETION BY HUMAN THYROID CELLS AFTER MONOLAYER CULTURE–COMPARISON OF NORMAL AND ADENOMATOUS CELLS
Authors: DAVIES T. F. , PLATZER M. , SCHWARTZ A. E. , FRIEDMAN E. 
Published: March 2008

SUMMARYWe have analysed immunoassayable thyroglobulin (hTg) secretion from both normal and abnormal isolated human thyroid cells after short‐term monolayer culture. All cells were sensitive to more than 10 μU/ml bTSH when assessed by intracellular cyclic AMP accumulation in the presence of a phosphodiesterase inhibitor. hTg release was stimulated in all cells by bTSH in a dose related manner and with a detectable response within 24 h. Basal hTg secretion rates were greater in cells derived from benign follicular adenomata (range 1‐1–2‐2 ng/105 cells/h, n=4) than in normal human thyroid cells (range 0‐1‐0‐65 ng). Therefore it appears likely that hTg secretion by adenomatous thyroid cells was a likely contributor to increased serum hTg in patients with single follicular adenomata. We conclude that simple human thyroid cell monolayers have potential for the further study of hTg secretion and its control by TSH.
RESPONSES TO ANALOGUES OF GROWTH HORMONE‐RELEASING HORMONE IN NORMAL SUBJECTS, AND IN GROWTH‐HORMONE DEFICIENT CHILDREN AND YOUNG ADULTS
Authors: GROSSMAN A. , SAVAGE M. O. , LYTRAS N. , PREECE M. A. , SUEIRAS‐DIAZ J. , COY D. H. , REES LESLEY H. , BESSER G. M. 
Published: March 2008

SUMMARYThree analogues of growth hormone‐releasing hormone (GHRH) have been compared in normal subjects. GHRH(1‐29)NH2 is equipotent to GHRH(1‐40); increasing doses from 10‐200 per subject augments the duration of stimulated growth hormone (GH) release, but the peak serum GH shows only a poor correlation with dose. The derivative D‐Ala2‐GHRH(1‐29)NH2 is no more potent than the unsubstituted GHRH(1‐29)NH2. In 20 children and young adults with growth hormone deficiency by conventional criteria, eight showed normal or only slightly subnormal peak serum GH responses to GHRH(1‐40) or GHRH(1‐29)NH2. These included two patients with tumours of the hypothalamus, as well as six with idiopathic isolated growth hormone deficiency or panhypopituitarism. A poor response to GHRH was generally seen in patients on long‐term GH therapy. Priming with GHRH, in either a single bolus or a continuous infusion, did not increase the GH response to GHRH. It is concluded that GHRH(1‐29)NH2 is a useful analogue in the testing of GH reserve in patients with growth hormone deficiency, and has considerable potential for long‐term therapy.
INHIBITION OF PHYSIOLOGICAL GROWTH HORMONE SECRETION BY ATROPINE
Authors: TAYLOR B. J. , SMITH P. J. , BROOK C. G. D. 
Published: March 2008

SUMMARYWe have investigated the effects of atropine (specific muscarinic cholinergic inhibition) on the nocturnal secretion of GH during the first cycle of stage IV sleep in six normal volunteers and three tall adolescents. Atropine was administered orally in a dose of 0·6 mg (n= 8) or 1·8 mg (n= 4) 30 min before expected sleep and the sampling repeated. Peak GH level without atropine was 45·3 mU/l (range 5·7 to 92·0): both doses of atropine abolished sleep associated GH secretion. Spontaneous daytime GH secretion was demonstrated during five 6 h sampling periods in three normal adults. There was a significant decrease in spontaneous daytime GH secretion when the sampling was repeated after atropine 0·6 mg or 1·8 mg. We conclude that inhibition of GH secretion using anticholinergic drugs should be further investigated in the management of excessive growth hormone secretion.
NALOXONE REDUCES THE FENFLURAMINE‐INDUCED PROLACTIN RELEASE IN MAN
Authors: FORESTA C. , SCANELLI G. , INDINO M. , FEDERSPIL G. , SCANDELLARI C. 
Published: March 2008

SUMMARYIn order to ascertain whether there is a relation between opioids and the serotoninergic system in prolactin (PRL) secretion increase, we investigated in seven healthy men (21 to 26 years of age) the effect of naloxone, a specific opioid antagonist, on PRL secretion induced by fenfluramine, a drug that stimulates serotonin release and inhibits its re‐uptake. We observed that subjects receiving fenfluramine (60 mg orally) had a significantly (P < 0·001) higher increase in PRL plasma levels than the controls receiving placebo. In all subjects naloxone infusion at a dose of 15 mg caused a significant reduction (P < 0·0005) in the PRL response to fenfluramine. Higher doses of naloxone (30 mg) do not further inhibit the PRL secretion induced by fenfluramine. These results suggest that naloxone may interact with opiate receptors on serotonin neurons thereby reducing the synthesis and release of serotonin. It seems that in man, therefore, there is an interplay between opiates and the serotoninergic system in the facilitatory influence on PRL release.
TESTOSTERONE REPLACEMENT IN HYPOGONADAL MEN: EFFECTS ON OBSTRUCTIVE SLEEP APNOEA, RESPIRATORY DRIVES, AND SLEEP
Authors: MATSUMOTO A. M. , SANDBLOM R. E. , SCHOENE R. B. , LEE KATHRYN A. , GIBLIN ELIZABETH C. , PIERSON D. J. , BREMNER W. J. 
Published: March 2008

SUMMARYThe obstructive sleep apnoea syndrome occurs predominantly in men. To determine the effect of testosterone on ventilatory function and whether testosterone may play a role in the development of obstructive apnoea, we performed waking ventilatory drive studies and sleep studies in five hypogonadal men. These androgen‐deficient subjects were studied both while receiving no treatment and after six weeks of testosterone replacement therapy (testosterone oenanthate 200 mg i.m. every 2 weeks). Hypoxic ventilatory drive decreased significantly, from 158 · 39 (mean · SEM) off testosterone to 88 · 19 on testosterone therapy (P < 0.05). Hypercapnoeic ventilatory drive did not change significantly on testosterone. Obstructive sleep apnoea developed in one man and markedly worsened in another man in association with testosterone administration. Both of these subjects also exhibited marked decreases in oxygen saturation with the development of cardiac dysrhythmias during sleep and large increases in haematocrit. The remaining three hypogonadal men did not demonstrate significant sleep apnoea either on or off testosterone. The percentage of sleep time spent in REM sleep increased from 14 · 3% to 22 · 2% when the men were receiving testosterone (P < 0.01), but the episodes of sleep apnoea tended to occur during non‐REM sleep. We conclude that in some hypogonadal men, replacement dosages of testosterone may affect ventilatory drives and induce or worsen obstructive sleep apnoea. The obstructive sleep apnoea syndrome is a potential complication of testosterone therapy. These results suggest that androgen levels present in normal man may play an important role in the pathogenesis of obstructive sleep apnoea.
MAGNESIUM ADMINISTRATION REVERSES THE HYPOCALCAEMIA SECONDARY TO HYPOMAGNESAEMIA DESPITE LOW CIRCULATING LEVELS OF 25‐HYDROXYVITAMIN D AND 1,25‐DIHYDROXY VITAMIN D
Authors: FUSS M. , COGAN E. , GILLET C. , KARMALI R. , GEURTS J. , BERGANS A. , BRAUMAN H. , BOUILLON R. , CORVILAIN J. 
Published: March 2008

SUMMARYThe effect of parenteral administration of magnesium was studied in five patients with hypomagnesaemic hypocalcaemia. The initial metabolic state was characterized by a normal level of serum immunoreactive parathyroid hormone (iPTH), and by low or undetectable serum 25‐hydroxyvitamin D (25OHD) and 1,25‐dihydroxyvitamin D (1,25 (OH)2D). A parathyroid response was elicited by the acute intravenous injection of magnesium chloride. In contrast, 1,25(OH)2D did not change up to 24 h after the injection. Intramuscular magnesium sulphate restored serum magnesium and calcium to normal, whereas iPTH was transiently increased. 25OHD remained low and unchanged. 1,25(OH)2D rose very slowly, but the correction of hypocalcemia began before any change in 1,25(OH)2D levels could be demonstrated. Thus, the early correction of hypocalcemia mainly depended on the restoration of an adequate parathyroid function independently of the secretion of 1,25(OH)2D.
GROWTH HORMONE RELEASING FACTOR‐TEST IN ACROMEGALY: COMPARISON WITH OTHER DYNAMIC TESTS
Authors: LOSA M. , SCHOPOHL J. , STALLA G. K. , MÜLLER O. A. , VON WERDER K. 
Published: March 2008

SUMMARYHuman pancreatic growth hormone releasing factor (hpGRF1–44) was given intravenously as a 100 μg bolus to 20 patients with active acromegaly. The GH‐responses were variable, ranging from an increase of 8 to 2813% from the basal level (mean ± SE, 428·136%). Sixteen GRF‐responders (Δ%± 100%) were arbitrarily distinguished from four GRF non‐responders, whose GH‐levels increased less than 100% from basal level after GRF‐administration. The outcome of the GRF‐test did not correlate with the results of other dynamic tests of GH‐secretion in acromegaly (oral glucose tolerance test, insulin hypoglycaemia, TRH‐, LHRH‐, CRF‐stimulation). In 10 patients who had not been treated before, the GH‐increments after GRF were higher than those in seven patients who had previously been subjected to transsphenoidal surgery, though they still had clinically and biochemically active acromegaly. Ten acromegalics, who were tested with GRF, were later treated surgically by the transsphenoidal route and were reevaluated with GRF‐stimulation 2 months after surgery. Eight patients appeared clinically cured of whom four had complete normalization and four had significantly lower basal and conventionally stimulated GH‐levels postoperatively. These patients also had normal postoperative GH‐responses to GRF, which had been significantly higher before surgery compared with normal controls. It is concluded that the GRF‐test in acromegaly does not help in establishing the diagnosis. The normalization of the GH‐response to GRF after transsphenoidal surgery seems to represent additional evidence for normalization of GH‐secretion, though the latter is not proven by the normal outcome of this test.
THE INFLUENCE OF OESTROGENS ON THE SENSITIVITY OF PRL, TSH AND LH TO THE INHIBITORY ACTIONS OF DOPAMINE IN HYPERPROLACTINAEMIC PATIENTS
Authors: VALCAVI R. , HARRIS P. E. , FOORD S. M. , DIEGUEZ C. , EVANS P. J. , PETERS J. R. , HALL R. , SCANLON M. F. 
Published: March 2008

SUMMARYThe effects of oestrogen priming on the response of serum PRL, LH and TSH to dopamine (DA) infusion have been studied in hyperprolactinaemia. Seven hyperprolactinaemic females (aged 22–57 years; basal PRL 911–5130 mU/1, normal >420 mU/1), had submaximal DA infusions (0·06 μg/kg/min) over 3 h. The DA was repeated at the same dose after pretreatment with ethinyl oestradiol (E2) 100 μg daily by mouth for 3 d, and after a further 2 week interval, following pretreatment with tamoxifen (TAM) 20 mg twice a day by mouth for 3 d. Ethinyl oestradiol pretreatment stimulated a rise in basal PRL levels in all subjects (mean ± SE, mU/1; 2903 ± 761 vs 2293 ± 684, P>0·05) while TAM produced a higher but more variable increase in basal PRL levels (mean ± SE, mU/1; 3402 ± 757, P= n.s.). The individual increments in basal PRL levels after both E2 and TAM pretreatment showed a significant positive correlation with the greater decrement in PRL levels during E2 and TAM primed DA infusions (E2, r= 0·93, P > 0·01, TAM, r= 0·83, P > 0·05). E2 pretreatment produced a rise in basal LH levels in 5/7 patients, and there was a significant positive correlation between the rise in basal LH levels after E2 and the decremental change in LH levels in E2 primed DA infusions (r= 0·94, P>0·01). Basal TSH levels were unaffected by E2 and TAM pretreatment, but during DA infusion there was a significantly greater decremental change following E2 pretreatment (sum of decrements, mean ± SE mU/1; 8·1 ± 1·58 vs 4·65 ± 1·23, P > 0·02). In conclusion, E2 and TAM increased PRL sensitivity to the inhibitory actions of DA treatment. In contrast, E2 but not TAM, exerted similar effects on the dopaminergic inhibition of LH and TSH.
SERUM SEX HORMONE CONCENTRATIONS IN INSULIN DEPENDENT DIABETIC WOMEN WITH AND WITHOUT AMENORRHOEA
Authors: DJURSING H. , HAGEN C. , ANDERSEN A. NYBOE , SVENSTRUP B. , BENNETT P. , PEDERSEN L. MØLSTED 
Published: March 2008

SUMMARYAbnormal steroid secretion may contribute to anovulation in insulin dependent diabetic patients with amenorrhoea. We have measured serum sex hormonebinding globulin (SHBG) and free and bound oestrogen and androgen levels in 17 such patients. As controls we included 17 patients with insulin dependent diabetes mellitus and normal menstrual cycles, 21 regularly menstruating normal women (both sampled during early follicular phase), and 23 non‐diabetic patients with amenorrhoea. The diabetic patients with normal cycles had significantly higher serum concentrations of Δ4‐androstenedione and testosterone than the normal women (P>0·01). The amenorrhoeic diabetics in contrast had significantly lower serum concentrations of SHBG, 5 α‐dihydrotestosterone and free and total oestradiol‐17β than either group of menstruating women (P>0·05), and significantly lower concentrations of Δ4‐androstenedione (P > 0·01), dehydroepiandrosterone sulphate (P > 0·01), testosterone (P > 0·01), and oestrone (P > 0·05), than the cycling diabetics. The two amenorrhoeic groups had similar free and bound sex hormone concentrations except that Δ4‐androstenedione levels were significantly lower in the diabetics (P>0·01). We conclude that the low sex hormone levels in diabetic women with amenorrhoea may be due to suppression of the hypothalamic‐pituitary axis in view of the impaired LH secretion found in these patients and that excess androgen secretion seems not to be of aetiological importance in amenorrhoea related to diabetes mellitus. The decreased steroid levels in amenorrhoeic diabetics is due to their suppressed ovarian function while the increased androgen levels in diabetics with regular cycles are probably of ovarian origin.
EFFECTS OF EXOGENOUS CATECHOLAMINES AND EXERCISE ON PLASMA MAGNESIUM CONCENTRATIONS
Authors: JOBORN H. , ÅKERSTRÖM G. , LJUNGHALL S. 
Published: March 2008

SUMMARYCatecholamines and physical exercise are known to influence the metabolism of several minerals in man, but the effects on magnesium (Mg) have been scarcely investigated. In the present study, infusion of adrenaline (5 μg/min for 30 min followed by 10 μg/min for 30 minutes) significantly reduced the plasma Mg levels in healthy males. This effect was abolished by simultaneous infusion of propranolol. Noradrenaline had no such effect. In order to stimulate endogenous catecholamine release healthy males carried out physical exercise in four different ways: (1) ergometer bicycling at maximum load until exhaustion with and without oral beta‐blockade, (2) ergometer bicycling with stepwise increasing load until exhaustion, (3) isokinetic maximal exercise with one leg, with blood sampling both from the venous effluent of the exercising leg and the opposite resting arm and (4) long‐term (60 min) steady state ergometer bicycling at approximately 65% of estimated maximum capacity. During short‐term (less than 20 min) intense exercise (i.e. experiments 1–3) the plasma Mg concentrations were increased. This was probably due to a reduction of plasma volume and to an influx of Mg to the vascular pool. During long‐term steady state exercise (experiment 4) the Mg levels were not significantly affected but decreased during the first hour of recovery. These results suggest that both the beta‐adrenergic system and muscular activity by itself affect Mg homeostasis.
THE RELATIONSHIP BETWEEN SERUM PROLACTIN AND IMMUNOCYTOCHEMICAL STAINING FOR PROLACTIN IN PATIENTS WITH PITUITARY MACROADENOMAS
Authors: ROSS R. J. M. , GROSSMAN A. , BOULOUX P. , REES LESLEY H. , DONIACH I. , BESSER G. M. 
Published: March 2008

SUMMARYWe have studied the relationship between mean pretreatment levels of serum prolactin and the presence of positive immunohistochemical staining for prolactin in the pituitary tumours of 55 patients. Pretreatment serum prolactin was significantly higher in patients with tumours showing many prolactin immunostaining cells than in those with none (P>0·001). When the pretreatment serum prolactin exceeded 6000 mU/1, the tumours contained over 90% of prolactin positive cells; one patient was an exception who had received longterm high dose bromocriptine therapy, and her tumour showed only occasional cells with positive staining. When the pretreatment serum prolactin level was under 2500 mU/1, a tumour was found which showed either no cells or fewer than 1% of cells which stained for prolactin. There was no significant difference in pretreatment serum prolactin levels between 11 patients with craniopharyn‐giomas and 34 patients with pituitary macroadenomas showing no prolactin immunostaining. Seventy‐one percent (32) of the 45 patients with craniophar‐yngiomas or tumours with negative immunostaining for prolactin, had raised pretreatment serum prolactin levels (above 360 mU/1) although this was usually only slightly elevated; the levels exceeded 2500 mU/1 in six (13%) of them (two craniopharyngiomas, four pituitary tumours) but in none did the levels exceed 6000 mU/1. Four of the 55 pituitary tumours showed occasional cells (less than 1%) that stained positively for growth hormone. In none of the patients with these tumours was there evidence of acromegaly or pathologically elevated circulating growth hormone levels.