bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE EFFECTS OF CYPROTERONE ACETATE AND ETHINYL OESTRADIOL ON CARBOHYDRATE METABOLISM
Authors: SEED M. , GODSLAND I. F. , WYNN V. , JACOBS H. S. 
Published: March 2008

SUMMARYCarbohydrate metabolism was studied in a group of 66 women, taking cyproterone acetate (CA) and ethinyloestradiol (EO) as anti‐androgen therapy for the treatment of hirsutism and/or acne. A reverse sequential treatment cycle was used and women were studied in two groups: the first when taking the combination of CA and EO during the first 12 days of the treatment cycle, and the second taking EO alone during days 13 to 22. The combination reduced fasting plasma glucose and raised fasting plasma insulin concentrations. There was deterioration of glucose tolerance with increased plasma insulin concentrations and these effects were progressive with time. The plasma insulin response to intravenous tolbutamide was increased by 50% but there was no accompanying change in the glucose nadir as compared with controls. These results show that the combination of CA and EO causes insulin resistance. Plasma C‐peptide concentrations following oral glucose were unchanged compared with controls. This shows that the observed hyperinsulinaemia was due to a reduction of hepatic uptake of insulin rather than its increased secretion. We propose that these effects are due to a CA‐induced elevation of fasting plasma insulin resulting in downregulation of hepatic insulin receptors with subsequent induction of insulin resistance and impairment of hepatic insulin uptake. C‐peptide concentrations following i.v. tolbutamide were significantly higher on treatment with CA and EO than in controls indicating increased pancreatic secretion of insulin. Tests carried out while patients were taking EO alone showed impairment of glucose tolerance only with no change in insulin levels. There was an increase in plasma insulin in response to tolbutamide but this was not significant. We conclude that these results are explained by a reduced but persisting effect of CA.
EFFECTS OF GRF(1–40) AND DOMPERIDONE ON GH SECRETION IN NORMAL MAN
Authors: GIUSTI M. , MAZZOCCHI G. , SESSAREGO P. , MIGNONE D. , LOMEO A. , MONACHESI M. , GIORDANO G. 
Published: March 2008

SUMMARYIn eight normal adult men pituitary secretion following GRF(1–40) was studied. GRF administration (50 μg i.v.) was followed by an increase in GH release with a peak value between the 15 and 60 min. No effects were noticed on LH, FSH, PRL, TSH and ACTH secretion. GH and PRL release was also studied after domperidone (DOM) (5 mg i.v./h), and GRF plus DOM. PRL increased significantly after DOM and GRF plus DOM. During GRF plus DOM a more marked GH release was observed in comparison with the hormone response to GRF alone at 15–45 and 120 min (P < 005). This phenomenon was found in six out of eight subjects studied. Mean peak and secretory area was greater (P < 005) after GRF plus DOM than after GRF alone. These data suggest that GRF(1–40) at the dose used is a useful tool in the study of GH secretion. The GH pattern during GRF plus DOM seems to indicate that dopaminergic tone may play a direct inhibitory role on GH secretion in man.
SERUM THYROGLOBULIN IN PATIENTS WITH AUTONOMOUS THYROID NODULES
Authors: MADEDDU G. , CASU A. R. , MARROSU A. , MARRAS G. , LANGER M. 
Published: March 2008

SUMMARYTo investigate further the relationship between thyroid hormones and thyroglobulin (TG) secretion, total and free thyroid hormone levels, TSH and its response to TRH and serum TG concentrations were determined in 61 patients with solitary autonomous thyroid nodules. Thyroid function varied widely from euthyroidism to clearcut thyrotoxicosis. Serum TG levels were significantly higher in patients than in normal controls. Individually they were above the normal range (> 50 ng/ml) in 95% of the patients, as well as in those with normal total and/or free thyroid hormone levels. Patients with high total and/or free thyroid hormone levels had higher TG concentrations than euthyroid patients. TG concentrations were significantly correlated with FT3 values. They were higher in patients in whom TSH was unresponsive to TRH than in the responsive groups. TG was also slightly higher in patients with hot nodules than in those with warm nodules. These data seem to indicate that TG is secreted along with thyroid hormones in the absence of any stimulatory action. It also is a sensitive index of thyroid hyperfunction. Twenty patients were controlled 6 months after nodulec‐tomy. TG levels, though significantly lower than in the preoperative state, were still higher than in normal subjects. This increase was attributed to persistent hyperthyroidism in two patients only. The observation that the increase in TSH after TRH stimulation in post‐operative patients was greater than that found in normal controls led us to believe that in most cases the high TG levels after surgery are due to stimulation of the normal thyroid tissue by rebound TSH secretion.
THE EFFECT OF ENDOGENOUS PROGESTERONE ON SERUM LEVELS OF 5α‐REDUCED ANDROGENS IN HIRSUTE WOMEN
Authors: DEWIS P. , NEWMAN M. , ANDERSON D. C. 
Published: March 2008

SUMMARYThis study was to examine indirectly the effect of endogenous progesterone, a known competitor for 5α‐reductase, on androgen metabolism in target organs in hirsute women. Serum levels of progesterone, testosterone (T), androstene‐dione (A), dihydrotestosterone (DHT) and 5α‐androstane 3α17β‐diol (3α‐diol) and sex hormone binding globulin (SHBG) were assessed serially over a four week period in normal women, six hirsute women with regular menstrual cycles, eight hirsute women with oligomenorrhoea (and presumptive polycystic ovaries) and seven non‐hirsute women with oligomenorrhoea. Serum T and A levels were significantly higher than normal in both hirsute and non‐hirsute women with oligomenorrhoea, while serum SHBG was significantly lower than normal in the two groups of hirsute women. The calculated free T level was higher than normal in all three groups of patients. DHT levels were not significantly different from normal in any of the three groups of patients. The 3α‐diol level showed considerable overlap with normal in all groups of patients and was only significantly higher than normal in hirsute women with oligomenorrhoea (P& lt;005). There was a small fall in DHT in the late luteal phase of the cycle of those women with a sustained rise in serum progesterone in the second half of the cycle, but no change in serum 3α‐diol. These studies suggest that serum 3α‐diol may not be as good an indicator of peripheral androgen metabolism in hirsute women as previously reported and that a rise in serum progesterone has only a minimal effect on circulating levels of the active 5α‐reduced androgen metabolites. Although in vitro 3α‐diol has been shown to be a potent inhibitor of 5α‐reductase this casts doubt on its role in this regard in vivo.
ENHANCED GLUCONEOGENIC CAPACITY FROM GLYCEROL IN HYPERTHYROID MAN: EVIDENCE IN FAVOUR OF A BETA‐ADRENERGIC MECHANISM
Authors: McCULLOCH A J. , STEELE N. R. , KENDALL‐TAYLOR P. , BAYLIS P.H , ALBERTI K.G.M.M. 
Published: March 2008

SUMMARYWe have previously shown that gluconeogenesis, assessed by glycerol clearance, is increased in hyperthyroid man. The mechanism underlying this change is uncertain but many of the metabolic changes found in hyperthyroidism are thought to be due to increased catecholamine sensitivity of peripheral tissues. To test the hypothesis that enhanced gluconeogenic capacity from glycerol in hyperthyroidism might be mediated via a β‐adrenergic mechanism we have estimated glycerol clearance in thyrotoxic subjects before and during treatment with a non‐selective β‐adrenergic blocking drug propranolol (Inderal LA). Control subjects of similar age and weight were also tested. In hyperthyroid subjects, blood glucose and blood glycerol concentrations were increased but blood lactate, pyruvate and alanine concentrations were normal. Glycerol clearance was increased and followed a double exponential decay with a shortened second component half‐time. Endogenous glycerol production was increased three fold. Following β‐blockade blood glucose and blood glycerol concentrations fell although blood glucose concentrations remained above normal values. Glycerol clearance and endogenous glycerol production were also decreased but remained significantly higher than in control subjects. Serum thyroxine and serum triiodothyronine concentrations showed no significant change although mean values fell by 10% and 17% respectively. We conclude that the increase in gluconeogenic capacity from glycerol in hyperthyroid subjects is mediated in part by a β‐adrenergic mechanism.
PLASMA RENIN ACTIVITY IN INSULIN‐DEPENDENT DIABETICS WITH RAISED GLOMERULAR FILTRATION RATE
Authors: WISEMAN M. J. , DRURY P. L. , KEEN H. , VIBERTI G. C. 
Published: March 2008

SUMMARYBasal and ambulant plasma renin activity (PRA) were measured in 12 insulin‐dependent diabetics (IDDS) with elevated glomerular filtration rate (GFR), 12 IDDs with normal GFR matched for age, sex and duration of diabetes and 12 age and sex matched non‐diabetic control subjects. The two diabetic groups did not differ with respect to extracellular fluid volume, urinary sodium excretion, arterial blood pressure, mean plasma glucose concentration or urinary glucose excretion. Basal PRA did not differ significantly between the three groups. Ambulant PRA was significantly higher (P < 002) in the group of IDDs with elevated GFR than in the control group. Our data suggest that, in IDDs with high GFR, haemodynamic alterations may stimulate a rise in PRA and thus angiotensin, a potent vasoconstrictor. Whether this represents an attempt of the renin‐angiotensin system to normalise GFR or is the result of insensitivity of the renal vasculature to circulating angiotensin remains to be established.
FETAL GROWTH CONTROL: THE ROLE OF INSULIN AND RELATED PEPTIDES
Authors: MILNER R. D. G. , HILL D. J. 
Published: March 2008

SUMMARYBoth insulin and the related peptides, the insulin‐like growth factors/somatomedins, may function as anabolic factors in the regulation of fetal body size. Infants born to women suffering from diabetes mellitus may show increased deposition of subcutaneous fat and enhanced lean body mass, findings reproduced in experimental animal fetuses with induced hyperinsulinaemia. Fetal adiposity may be associated with a life‐time tendency to obesity and its associated diseases. Insulin‐like growth factors I (IGFI) and II are present in the circulation of the newborn infant and animal fetus and correlate positively with birth size. The fetal tissues are biologically responsive to IGFs in vitro and are rich in specific cell membrane receptors, those predominantly recognizing IGFI being structurally and functionally similar to the insulin receptor. Insulin could theoretically influence fetal tissues by an interaction with either the insulin or IGF receptor. IGF release is a property of multiple fetal tissues in vitro, but, in contrast to postnatal life, is not dependent on growth hormone. Fetal IGF production may be influenced by placental lactogen, especially IGFII which rapidly declines in the circulation following parturition in the rat and sheep. A positive association also exists between circulating levels of insulin and IGFs when the former is experimentally manipulated in the animal fetus. Similarly the infant born with transient diabetes mellitus has low cord blood levels of insulin and IGFI. Insulin has a dual role in prenatal life. In the last trimester insulin functions as a glucoregulatory hormone, but from much earlier in gestation creates an anabolic environment in the fetus supplied with optimal nutrients. This latter mechanism of action is unclear and probably heterogenous, but in overview is permissive rather than obligatory. In contrast the growth‐promoting role of the IGFs is direct but their interaction with fetal tissues, and thus the overall emphasis of fetal growth, may be paracrine.
HYPOMAGNESAEMIA: STUDIES OF PARATHYROID HORMONE SECRETION AND FUNCTION
Authors: ALLGROVE J. , ADAMI S. , FRAHER L. , REUBEN A. , H.O'RIORDAN J. L. 
Published: March 2008

SUMMARYNine patients with hypomagnesaemia have been studied. Six had magnesium deficiency secondary to malabsorption or diarrhoea and three had excessive urinary losses of magnesium. Hypocalcaemia was also present in eight. Parathyroid hormone (PTH) was measured using amino‐terminal and carboxyterminal specific immunoradiometric assays and also, in one patient, using a cytochemical bioassay. Amino‐terminal PTH (N‐PTH) varied directly with the concentration of magnesium; carboxy‐terminal PTH (C‐PTH) was raised in all patients. When magnesium was injected, both N‐PTH and C‐PTH rose regardless of the initial concentration, indicating that hypomagnesaemia was limiting PTH secretion. The clearance of endogenous PTH was measured in one patient, after injection of magnesium. Seven minutes after reaching its peak, C‐PTH had fallen to 69% and N‐PTH fell to 22% of its maximum values; the initial half life of N‐PTH was less than 2 min. In the same study biologically active PTH (bio‐PTH) disappeared rapidly with a half‐time of disappearance of 1–2 min. Responsiveness to PTH was measured by the rise in plasma cyclic 3′5′‐adenosine monophosphate (cAMP) following PTH injection. The rise in plasma cAMP was inversely related to the concentrations of magnesium and PTH at the time. It is suggested that the concentration of PTH rather than the degree of hypomagnesaemia is the most important factor determining the responsiveness of target tissues to PTH in magnesium deficiency,
STUDIES IN CONSTITUTIONALLY TALL ADOLESCENTS: SOMATOSTATIN DECREASE ASSOCIATED WITH GROWTH HORMONE INCREASE AFTER TRH INJECTION
Authors: BLANCO MATILDE GARCIA , BRION DANIELE EVAIN 
Published: March 2008

SUMMARYThe paradoxical GH response to TRH observed in certain adolescents with constitutional tall stature is associated with a 60% fall in plasma levels of somatostatin. Conversely, those tall subjects who do not show a GH increase after TRH, or during a saline control infusion maintain steady levels of somatostatin in plasma. It is thus hypothesized that the GH release after TRH is due to a decreased inhibitory effect of somatostatin at the pituitary level and that this reduced effect may play an aetiological role in certain children with ‘constitutional’ tall stature.
ADRENALINE CAUSES HYPOKALAEMIA IN MAN BY β2 ADRENOCEPTOR STIMULATON
Authors: And A. D. STRUTHERS , REID J. L. 
Published: March 2008

SUMMARYIncreased circulating adrenaline produces systemic hypokalaemia by the stimulation of a membrane bound Na/K ATPase. In man, this enzyme appears to be linked to an adrenoceptor of the β‐subtype. We have further studied the subtype of β‐adrenoceptor involved by infusing adrenaline intravenously in normal volunteers after pretreatment with either a selective β2 antagonist (ICI 118551) or placebo. During the adrenaline infusion the serum potassium fell from 4.08 ± 0.21 to 3.32 ± 0.25 mmol/1 (P <0.002). This adrenaline induced hypokalaemia was completely blocked by ICI 118551 (3.82 ± 0.13 to 4.03 ± 0.22 mmol/1, NS). Adrenaline also caused electrocardiographic changes of T wave flattening (–1.8 ± 1.5 mm, P <005) whereas the T wave height increased after ICI 118551 (51.0 ± 0.9 mm, P <005). This suggests that adrenaline acts via β2 adrenoceptors in man to cause potassium influx and systemic hypokalaemia.
THE EFFECT OF PLASMA GLUCOSE ON THE GROWTH HORMONE RESPONSE TO HUMAN PANCREATIC GROWTH HORMONE RELEASING FACTOR IN NORMAL SUBJECTS
Authors: SHARP P. S. , FOLEY K. , CHAHAL P. , KOHNER E. M. 
Published: March 2008

SUMMARYPituitary responsiveness to 44 amino acid human pancreatic growth hormone releasing factor was tested under conditions of euglycaemia and hyperglycaemia in six normal subjects. A 100 μg dose of growth hormone releasing factor was given at a fasting blood glucose of 5.1 ± 0.4 mmols/1 (mean ± S.D.), and at a blood glucose level of 10.9 ± 1.5. Under conditions of hyperglycaemia, the GH response to releasing factor was significantly depressed when compared to results obtained at fasting blood glucose (n= 6, t = 3.902, P= 0.0114). This is in keeping with the hypothesis that hyperglycaemia, mediated by the hypothalamus, causes decreased pituitary sensitivity to natural growth hormone releasing hormone.
THE PROLACTIN RESPONSE TO SUCKLING
Authors: GLASIER ANNA , MCNEILLY A. S. , HOWIE P. W. 
Published: March 2008

SUMMARYChanges in prolactin concentration during single suckling episodes in twenty breast‐feeding women from four to 40 weeks post partum have been investigated. Basal prolactin concentration and the increase in prolactin secretion in response to single suckling episodes and amount of milk taken by the infant were both independent of time post partum until the introduction of supplementary feeds, when a significant decrease with time was apparent. Basal concentrations of prolactin were dependent upon the interval between suckling episodes, and the magnitude of the prolactin response varied with the time of day when suckling took place. The relationship between acute suckling episodes and the long term pattern of prolactin secretion over time post partum is discussed.
MEASUREMENT OF IMMUNOREACTIVE γ‐MSH IN HUMAN PLASMA
Authors: HALE ANN C. , RATTER SALLY J. , TOMLIN SUSAN J. , LYTRAS N. , BESSER G. M. , REES LESLEY H. 
Published: March 2008

SUMMARYA radioimmunoassay for immunoreactive γ‐MSH (IR‐γ‐MSH) in human plasma has been developed. The assay is capable of detecting normal basal circulating levels which range from < 20‐100 ng/1 at 0900 h. Plasma levels are raised concomitantly with ACTH during insulin induced hypoglycaemia and CRF stimulation and suppressed with dexamethasone. Chromatographic characterisation of IR‐γ‐MSH in plasma demonstrates a major peak of IR‐γ‐MSH, corresponding to purified glycosylated N‐terminal pro‐opiome‐lanocortin 1‐76, when IR‐γ‐MSH is secreted from the pituitary. In contrast IR‐γ‐MSH produced ectopically appears to be heterogeneous.
SERUM THYROGLOBULIN LEVELS IN PRETERM NEONATES
Authors: NAYER PH. DE , CORNETTE C. , VANDERSCHUEREN M. , EGGERMONT E. , DEVLIEGER H. , JAEKEN J. , BECKERS C. 
Published: March 2008

SUMMARYSerum thyroglobulin (Tg) levels were determined in preterm neonates. Very high values were found at birth. A significant negative correlation was observed between Tg levels and gestational age. A longitudinal study indicates that a very sharp decrease in Tg levels occurred after birth. Three weeks after birth, the values were close to the values of full‐term neonates. These high hTg values could result either from an increased turnover of hTg or from a lower clearance rate of this iodoprotein.
A SIMPLE DHEAS LOADING TEST IN THE ANTEPARTUM DIAGNOSIS OF PLACENTAL SULPHATASE DEFICIENCY
Authors: SELBY C. , JEFFCOATE W.J. , ROSE F.A. , TAYLOR N.F. 
Published: March 2008

SUMMARYThe accurate antenatal diagnosis of placental sulphatase deficiency (PSD) is essential if this condition is to be distinguished from others in which levels of oestrogen are low. In this study we have evaluated a simple protocol determining the serum oestradiol response to 50 mg of dehydroepiandrosterone sulphate (DHEAS) given intravenously to twelve women with low serum or urinary oestrogens. Seven of the women had PSD confirmed by other means, the remaining five had other reasons for the low oestrogen levels. In affected pregnancies the rise in oestradiol was lower, the peak occurred earlier and the level fell towards baseline at 60 min. In the unaffected women, timing of the peak value was not consistent and there was no trend towards basal values at 60 min. There was clear discrimination between the two groups at all times after the injection. but the separation was greater at 60 min.
THE TREATMENT OF HYPOGONADOTROPHIC HYPOGONADISM IN MEN BY THE PULSATILE INFUSION OF LUTEINISING HORMONE‐RELEASING HORMONE
Authors: MORRIS D. V. , ADENIYI‐JONES R. , WHEELER M. , SONKSEN P. , JACOBS H. S. 
Published: March 2008

SUMMARYThe effects of chronic subcutaneous infusion of luteinising hormone‐releasing hormone (LHRH) have been studied in a group of 17 male patients with hypogonadotrophic hypogonadism (HH). Ten of the patients had primary and seven secondary failure of gonadotrophin release, and all but four had previously been treated with gonadotrophin injections. Treatment was continued for between one and 18 months and was well tolerated by all except one patient who became allergic to LHRH. An increase in the basal gonadotrophin concentrations occurred in all except four patients within one week of the initiation of therapy, and this was associated with a rise in the serum testosterone level in eight patients. Increased spermatogenesis was demonstrated in seven cases and three pregnancies have resulted thus far. Pituitary desensitisation to the effects of LHRH was found in five subjects with primary HH who failed to produce any increase in testosterone secretion despite an initial stimulation of gonadotrophin release. We conclude that chronic pulsatile infusion of LHRH is an effective technique for the treatment of some cases of hypogonadotrophic hypogonadism.
RESPONSE OF CIRCULATING SOMATOSTATIN, INSULIN, GASTRIN AND GIP, TO INTRADUODENAL INFUSION OF NUTRIENTS IN NORMAL MAN
Authors: LUCEY M. R. , FAIRCLOUGH P. D. , WASS J. A. H. , KWASOWSKI P. , MEDBAK S. , WEBB J. , REES L. H. 
Published: March 2008

SUMMARYWe have studied the effect of direct infusion of nutrients into the duodenum of normal subjects on circulating plasma somatostatin, insulin, gastrin and gastric inhibitory polypeptide (GIP) levels. Six normal subjects were given on four separate occasions 150 ml of isotonic solutions containing 100 calories of carbohydrate, protein, or fat, and a control solution of saline, by infusion into the second part of the duodenum. Plasma somatostatin rose slightly after carbohydrate, mean basal 30 ± 3 pg/ml, peak 46±16 pg/ml at 15 min; and more markedly after protein, peak 57 ± 9 pg/ml at 30 min. However, fat was the most potent intraduodenal stimulus to plasma somatostatin release into circulation, peak 101 ± 11 pg/ml at 30 min. The plasma insulin rise was greatest after carbohydrate, peak 68 ± 10 i.u., but there was a significant rise after protein also, peak 34 ±6 i.u. Plasma gastrin rose significantly after protein only, peak 70 ± 22 pg/ml. Plasma GIP rose markedly after carbohydrate, basal 506 ± 50 pg/ml, peak 1480 ± 120 pg/ml. Protein was also a potent stimulus of circulating plasma GIP release, peak 1200 ± 190 pg/ml, while fat was the least potent, peak 730±190 pg/ml. Thus, calorie for calorie, fat is the most potent intraduodenal nutrient stimulus of circulating somatostatin. We postulate therefore that somatostatin may be an enterogastrone–a circulating hormone released by intraduodenal fat which inhibits gastric acid secretion. Fat is the least potent intraduodenal nutrient stimulus of circulating GIP release. This is evidence against the hypothesis that circulating GIP acts as an enterogastrone.