bluuebunny/crossref_metadata_2025_split huggingface dataset:
PULSATILE RELEASE OF LH AND OESTRADIOL DURING THE PERIOVULATORY PERIOD IN WOMEN
Authors: DJAHANBAKHCH O. , WARNER P. , MCNEILLY A. S. , BAIRD D. T. 
Published: March 2008

SUMMARYBlood was collected every 8 h in five women from Day 10 of the menstrual cycle for 5–7 d for the measurement of LH, oestradiol and progesterone. In all women the LH surge started between 2400 and 0800 h before there was any significant decline in the concentration of oestradiol. In order to investigate the pulsatile secretion of LH and estradiol during the mid‐cycle surge, blood samples were collected every 5 min for up to 5 h. Immediately before and during the LH surge there were numerous episodic pulses of LH with an interpulse interval (44 ± 7 min) very similar to that observed in two women with hypergonadotrophic hypogonadism (48 min). The concentration of oestradiol fluctuated in a similar manner although it was not always possible to relate each pulse of oestradiol to a corresponding pulse of LH. The mid‐cycle surge of LH is characterized by frequent pulses of high amplitude. These results are compatible with the view that the positive feedback effect of oestradiol is due not only to enhanced sensitivity of the anterior pituitary to LHRH but also to the high frequency of LHRH pulses released from the hypothalamus.
THE INHIBITION BY ETOMIDATE OF THE 11β‐HYDROXYLATION OF CORTISOL
Authors: FRY D. E. , GRIFFITHS H. 
Published: March 2008

SUMMARYThe effect of a sleep‐dose of etomidate on the plasma concentrations of cortisol, 11‐deoxycortisol and 17αOH‐progesterone was investigated in eight patients; two other patients received thiopentone. Blood samples were collected at 0, 15 and 30 min after etomidate or thiopentone when an injection of tetracosactrin was given and a final sample was collected at 60 min. The plasma cortisol response to tetracosactrin was depressed below normal in patients given etomidate, and the 11‐deoxycortisol response was very high, ranging from 36·4 to 184·7 nmol/1. The two patients that received thiopentone had a normal response to all steroids. The identity of the plasma 11‐deoxycortisol in two patients was confirmed by high‐performance liquid chromatographic separation and quantification by both spectrophotometric and radioimmunoassay measurements. These results suggest that a single dose of etomidate inhibits 11β‐hydroxy]ation of cortisol.
EVIDENCE FOR DECREASED ENDOGENOUS DOPAMINE AND OPIOID INHIBITORY INFLUENCES ON LH SECRETION IN POLYCYSTIC OVARY SYNDROME
Authors: CUMMING D. C. , REID R. L. , QUIGLEY M. E. , REBAR R. W. , YEN S. S. C. 
Published: March 2008

SUMMARYThe inhibitory role of the dopaminergic and opioidergic mechanisms in the control of LH secretion in patients with polycystic ovary syndrome (PCO) was evaluated. The administration of an opiate receptor antagonist, naloxone, of a dopamine receptor antagonist, metoclopramide, or of human synthetic βh‐endorphin, were unable to alter LH secretory activity in patients with PCO. Since identical doses of these antagonists and the opiate agonist have elicited respectively a rise and fall of LH levels in normal cycling women, these findings suggest that an underlying hypothalamic component of defect in endogenous dopamine and opioid control may be responsible for the inappropriate gonadotrophin secretion in this syndrome.
DIURNAL PROLACTIN CHANGES IN HUMAN CEREBROSPINAL FLUID
Authors: BARRECA T. , PERRIA C. , FRANCESCHINI R. , SIANI C. , MESSINA V. , FRANCAVIGLIA N. , ROLANDI E. 
Published: March 2008

SUMMARYEight adult male patients suffering from hydrocephalus of differing aetiologies were investigated in order to detect the existence of diurnal variations of prolactin (PRL) concentration in human cerebrospinal fluid (CSF). Blood and ventricular CSF samples were taken every 2 h during the day (0800–2200 h) and every hour during the night (2300–0700 h). CSF mean PRL levels showed significant nyctohemeral variations with low levels (2·1 ± 0·3 ng/ml) during day‐time and higher levels at night (3·3 ± 0·1 ng/ml), similar to that observed in serum (PRL values: 16·4 ± 5·2 and 24·8 ± 4·3 ng/ml during day and night periods respectively). The presence of a 24 h CSF PRL secretory profile similar to that in serum was shown in six patients with normal 24 h mean PRL values and normal diurnal changes in serum. In two patients with an altered serum 24 h secretory pattern no significant nyctohemeral variations in CSF PRL levels were found. Present data show the existence in man of nyctohemeral variations in CSF PRL content related to the 24 h changes of PRL levels in serum.
THE THYROID FUNCTION IN YOUNG MEN DURING PROLONGED EXERCISE AND THE EFFECT OF ENERGY AND SLEEP DEPRIVATION
Authors: OPSTAD P. K. , FALCH D. , ØKTEDALEN O. , FONNUM F. , WERGELAND R. 
Published: March 2008

SUMMARYThyroid function has been investigated in 24 young military cadets participating in a 5 d ranger training course with heavy physical excercise, calorie deficiency and deprivation of sleep. The cadets were divided into three groups, each differing in the amount of sleep and food consumption. The serum levels of thyroid hormones (T4, FT4, T3, rT3) and TBG showed a biphasic pattern during the course. Initially there was an increased secretion concomitant with an increased deiodination of T4 to T3 and rT3 mainly due to physical exercise. When the activities lasted for several days without sufficient food supply the thyroid secretion decreased simultaneously with an alteration of the peripheral conversion of T4 to rT3 instead of T3. A significant correlation was found between the changes in total and free thyroxine (r= 0·9) and between the increase in rT3 and decrease in T3 (r= 0·6). TSH decreased during the first day of activities and remained low throughout the course. The TSH response to TRH stimulation was greatly reduced during the course due to physical exercise and calorie deficiency. The present investigation demonstrates that the thyroid function is strongly affected by prolonged physical exercise and a negative energy balance, whereas sleep deprivation does not have any significant influence. The results indicate that the alteration observed is not regulated just by the hypothalamo‐pituarity‐thyroid‐axis alone.
DISSOCIATION OF ADRENARCHE AND GONADARCHE IN DIABETES MELLITUS
Authors: COHEN H. N. , PATERSON K. R. , WALLACE A. M. , BEASTALL G. H. , MANDERSON W. G. , MacCUISH A. C. 
Published: March 2008

SUMMARYSerum concentrations of testosterone and dehydroepiandrosterone sulphate (DHAS) have been measured in 10 stable insulin‐dependent diabetic (IDD) males (chronological age (CA) range 13·0‐17·5 years). Their results have been compared with those of a control population of 69 non‐diabetic males who presented with mild constitutional growth delay and whose skeletal maturity and pubertal development were similar to the diabetic subjects. Within bone ages (BA) 11·0–14·5 years no significant difference was observed between the serum testosterone concentrations of the diabetic patients and controls: diabetic males, 8·2 (0·3–25) nmol/1 (median and range); controls, 7·0 (< 0·3–23) nmol/1. In contrast, within BA 11·0–14·5 years, the diabetic males had significantly lower serum DHAS concentrations: diabetic males, 1·1 (0·7–4·2) μmol/1; controls, 3·7 (0·7–5·6) μmol/1 (P < 0·001). The serum DHAS concentrations of the diabetic males were also significantly lower than the controls when matched separately for pubic hair and genital development, testicular volume and serum testosterone, (in each comparison P < 0·02). Serum DHAS concentrations of the diabetic males did not correlate significantly with CA, BA, BA delay (CA‐BA), age of onset of diabetes, duration of diabetes, or glycosylated haemoglobin (GHb), but significant correlation was observed between BA delay and duration of diabetes, r= 0·65, P < 0·05. We conclude that gonadarche appears to proceed despite delayed adrenarche in IDD males. This study presents further evidence in favour of adrenarche and gonadarche being independent physiological events. The causes and clinical significance of low serum DHAS concentrations in adolescent diabetic males remain to be established.
DIFFERENTIAL DIAGNOSIS BETWEEN HYPOTHALAMIC AND PITUITARY hGH DEFICIENCY WITH THE AID OF SYNTHETIC GH‐RH 1–44
Authors: LARON Z. , KERET R. , BAUMAN B. , PERTZELAN A. , BEN‐ZEEV Z. , OLSEN D. B. , COMARU‐SCHALLY A. M. , SCHALLY A. V. 
Published: March 2008

SUMMARYSynthetic GH‐RH 1–44 administered as an intravenous bolus (1 μg/kg) evoked a marked hGH rise (>20 ng/ml) in three children with constitutional short stature and in two of eight children diagnosed as having hGH deficiency by insulin hypoglycaemia and/or clonidine tests. As judged by the intensity of the hGH response to the dose employed and the peak time, GH‐RH 1–44 may be as potent as GH‐RH 1–40 in children. It is concluded that GH‐RH is an important addition to the endocrine armamentarium, providing the means for differentiation between hypothalamic and pituiary hGH deficiency in a simple test which is devoid of side effects.
A CYTOCHEMICAL SECTION BIOASSAY FOR PLASMA TRILOSTANE: AN ORALLY ACTIVE INHIBITOR OF 3β‐HYDROXYSTEROID DEHYDROGENASE ACTIVITY
Authors: EARNSHAW R. J. , MITCHELL R. , ROBERTSON W. R. 
Published: March 2008

SUMMARYTrilostane is a competitive inhibitor of 3β‐hydroxysteroid dehydrogenase activity in vitro and an orally active inhibitor of steroidogenesis in vivo. A cytochemical section bioassay for this drug (4α, 5‐epoxy‐17β‐hydroxy‐3‐oxo‐5α‐androstane‐2α‐carbonitrile) in human plasma has been developed. The assay is based upon the inhibition of 3β‐hydroxysteroid dehydrogenase (3β‐HSD) activity in the corpus luteum of unfixed tissue sections (6 μm) of the mature dioestrous rat ovary. Trilostane is extracted from plasma by a simple chloroform procedure. The stanuard curve (0·15–2·5 μmol/I pure trilostane) exhibits a four‐fold change in 3β‐HSD activity and is constructed in the presence of extract from control plasma pools. The detection limit of the plasma assay is 2μmol/I trilostane after allowing for dilution effects and recovery losses. This level gives a significantly different response from the zero quality control (P<0·05) and has an inter‐assay coefficient of variation of < 15%. No false positives have been recorded to date and the majority of samples from subjects receiving therapeutic doses of the drug have levels of > 2 μmol/1. Intra‐ and inter‐assay coefficients of variation using both plasma quality controls and unknown samples are 4% (n= 15) and 13·9% (n= 27) respectively. Recovery is 80·9% (n= 13) and 79·10% (n= 10) for plasma quality controls containing 12 and 4·8 μmol/1 trilostane respectively. Dilutions (up to 1:5) of plasma extracts are parallel to the standard curve and the assay throughput is approximately 16 samples/week technician. Testosterone, oestradiol, oestriol, dehydroepiandros‐terone (DHEA), DHEA‐sulphate, progesterone, cortisol, androstenedione and dexamethasone (all at 1 μmol/1) were without effect on the 3β‐HSD assay. It is concluded that the bioassay is suitable for assaying trilostane in human plasma.
ALTERATION OF HORMONE LEVELS IN NORMAL MALES GIVEN THE ANABOLIC STEROID STANOZOLOL
Authors: SMALL M. , BEASTALL G. H. , SEMPLE C. G. , COWAN R. A. , FORBES C. D. 
Published: March 2008

SUMMARYAnabolic steroids have widespread metabolic effects but, to date, their proven clinical indications have been limited. Recently the 17 α‐alkylated steroid, stanozolol, has been shown to be of value in a variety of commonly occurring vascular diseases. Its endocrine effects have received little attention and we have investigated the effect of administering a 14 d course of stanozolol (10 mg orally per day) on a variety of important hormonal pathways in nine healthy male subjects. Significant changes occurred as follows: a 55% reduction in serum testosterone levels was noted and was accompanied by reductions in ‘derived’ free testosterone, sex hormone binding globulin and LH levels; total T4 and T3 levels fell in association with a decrease in thyroxine binding globulin, but no alteration was detected in TSH or free T4 levels. Changes in vitamin D status, with falls in 25‐hydroxycholecalciferol and vitamin D binding globulin were also observed. These effects were reversible on stopping treatment. Stanozolol therapy therefore leads to a number of hormonal changes, probably by an action at both pituitary and hepatic levels.
GONADOTROPHIN RESPONSES TO GnRH IN PRECOCIOUS PUBERTY TREATED WITH GnRH ANALOGUE
Authors: DONALDSON M. D. C. , STANHOPE R. , LEE T. J. , PRICE D. A. , BROOK C. G. D. , SAVAGE D. C. L. 
Published: March 2008

SUMMARYThe gonadotrophin releasing hormone analogue Buserelin was given by intranasal spray to 13 children with precocious puberty. The LH responses to GnRH reverted to prepubertal levels in the boys on 200–400 μg daily of the analogue while doses of 400–1200 μg daily were needed to suppress the girls. The significance of this apparent sex difference is uncertain.
THE RESPONSE OF NORMAL SUBJECTS AND PATIENTS WITH IDIOPATHIC GROWTH HORMONE DEFICIENCY TO CONTINUOUS INFUSION OF HUMAN PANCREATIC GROWTH HORMONE RELEASING FACTOR 1–44
Authors: DAVIES R. R. , TURNER S. J. , PARKIN J. M. , JOHNSTON D. G. 
Published: March 2008

SUMMARYThe GH response to a prolonged continuous infusion of human pancreatic growth hormone releasing factor (hpGRF 1–44), 0.3 μg/kg/h was evaluated in seven patients with severe idiopathic GH deficiency, one patient with partial deficiency and in seven normal controls. Normal controls had a multiphasic response with a first peak between 15 and 90 min of 13.6 to 88.5, mean 45.6 mU/l and a second peak between 105 and 195 min of 8.8 to 73.1, mean 33.8 mU/l. However, the magnitude and pattern of response were highly variable. Six of the seven patients with severe GH deficiency had a response with a maximum level between 30 and 90 min of 3.3 to 7.5, mean 4.8 mU/l. Mean levels remained greater than 2.0 mU/l throughout the infusion but further peaks were absent or minimal. The patient with partial GH deficiency responded in a normal manner. hpGRF 1–44 by continuous infusion thus induced GH release in seven of eight patients with idiopathic GH deficiency though the response was impaired and the pattern of secretion abnormal in severely deficient patients.
THYROREGULATORY CHANGES ASSOCIATED WITH SMOKING IN 70‐YEAR‐OLD MEN
Authors: EDÉN S. , JAGENBURG R. , LINDSTEDT G. , LUNDBERG P. ‐A. , MELLSTRÖM D. 
Published: March 2008

SUMMARYIn a previous study we have analysed serum free T4 concentrations in a representative population of 70‐year‐old men. In the present study the effect of previous or present tobacco smoking on free T4, T4, T3, rT3, TSH and thyroid hormone binding proteins was analysed in 181 of the 460 men, excluding those with past or present goitre, those who were obviously ill or had died between 70 and 75 years of age and those who had any disease or medication influencing free T4 concentrations. Smokers had higher T4 and rT3 levels, and lower TSH levels but T3 levels no different from non‐smokers. The difference in T4 levels, but not rT3 or TSH levels, between smokers and non‐smokers could be attributed to differences in body mass and also to differences in TBG levels. The results indicate that tobacco smoking is associated with long‐term alterations in thyroregulatory function.
TWO TYPES OF THYROID FUNCTION‐BLOCKING ANTIBODIES IN AUTOIMMUNE ATROPHIC THYROIDITIS AND TRANSIENT NEONATAL HYPOTHYROIDISM DUE TO MATERNAL IgG
Authors: TAKASU N. , NAKA M. , MORI T. , YAMADA T. 
Published: March 2008

SUMMARYWe examined the effects of IgG from four patients with autoimmune atrophic thyroiditis on cAMP responses and iodine metabolism (post‐receptor processes), using cultured thyroid cells. We found two types of thyroid function‐blocking antibodies: (1) one blocks TSH binding to its receptors and inhibits TSH‐stimulated cAMP responses but does not block cAMP‐stimulated iodine uptake and organification; (2) the other blocks TSH binding to its receptors, inhibits TSH‐stimulated cAMP responses and does block cAMP‐stimulated iodine uptake and organification (post‐receptor processes). Among the four patients with autoimmune atrophic thyroiditis, three had TSH binding blocking antibodies only and one had antibodies which block post‐receptor processes. These antibodies might be responsible for thyroid dysfunction in autoimmune atrophic thyroiditis. The daughter of one of the women with autoimmune atrophic thyroiditis had transient neonatal hypothyroidism and recovered spontaneously from the hypothyroid state with the disappearance of the maternal blocking antibodies.
DIFFERENTIAL TSH AND PRL RESPONSES TO DOPAMINE RECEPTOR BLOCKADE IN ACROMEGALY
Authors: PRESCOTT R. W. G. , WEIGHTMAN D. R. , KENDALL‐TAYLOR PAT , JOHNSTON D. G. 
Published: March 2008

SUMMARYThe serum TSH and prolactin responses to dopamine receptor blockade (domperidone 10 mg i.v.) were measured in eight acromegalic subjects and seven normal controls. The serum TSH response was exaggerated in acromegalics when compared to controls (sum of the increments 12–2 ± 2–8 mU/1 and 40 ± 1 ‐2 mU/1 respectively P & lt; 0–05), whereas the serum prolactin response was blunted (sum of the increments 5029±1377 mU/1 and 14 673 ± 2889 mU/1 respectively P <0–01). Dopamine receptor blockade did not significantly alter basal growth hormone levels in either group. To ascertain whether this response was merely a reflection of high circulating growth hormone levels six normal controls were pretreated for 24 h with either intramuscular growth hormone (three injections of 4 IU) or an equivalent volume of saline before the administration of domperidone (10 mg i.v.). The serum TSH and prolactin responses were not affected by prior growth hormone treatment. The opposite TSH and prolactin responses to dopamine blockade do not allow any firm conclusions to be made about the level of hypothalamic dopamine activity in acromegaly.
ORAL GLUCOSE INHIBITS GROWTH HORMONE SECRETION INDUCED BY HUMAN PANCREATIC GROWTH HORMONE RELEASING FACTOR 1–44 IN NORMAL MAN
Authors: DAVIES R. R. , TURNER S. , JOHNSTON D. G. 
Published: March 2008

SUMMARYThe interaction between the inhibitory effect on growth hormone secretion of a 75 g oral glucose load and the stimulatory effect of human pancreatic growth hormone releasing factor 1–44 (hpGRF 1–44, 10 μg i.v.) has been studied in six normal subjects. hpGRF 1–44 alone induced a rise in growth hormone concentrations (maximum mean ± SEM, 16–5 ± 1.7 mU/1 15 min after injection) while growth hormone levels were suppressed by oral glucose alone (& < 1 ‐5 mU/1 from 45 to 135 min after glucose ingestion). When hpGRF 1–44 was injected 60 min after oral glucose, the growth hormone response was attenuated (maximum, 6.7±1.4 mU/1 at 15 min, P<005). Increments of blood glucose within the physiological range diminish the growth hormone response to hpGRF 1‐44 in normal man.
PULSATILE SECRETION OF LH IN RELATION TO THE RESUMPTION OF OVARIAN ACTIVITY POST PARTUM
Authors: GLASIER ANNA , McNEILLY A. S. , HOWIE P. W. 
Published: March 2008

SUMMARYChanges in the pulsatile pattern of LH secretion in relation to the resumption of ovarian activity post partum have been studied in breast feeding mothers. Basal concentrations of LH were significantly lower than normal both when ovarian activity was completely suppressed and when there was evidence of some follicular development prior to the resumption of menstruation. Once menstruation resumed basal concentrations of LH were unchanged whether ovulation occurred or not. No difference in the frequency or amplitude of pulses in LH secretion could be found at any stage post partum in either breast or bottle feeding women. FSH levels remained constant throughout the post partum period while mean concentrations of prolactin fell as ovarian activity returned to normal. However, during the period of complete suppression of ovarian activity in breast feeding women, two patterns of pulsatile secretion of LH were observed. In 76% of observation periods, basal levels of LH were lower than normal and were characterized by low frequency and low amplitude pulses of LH. In contrast, in the remaining 24% of observation periods, basal levels and pulse amplitude and frequency of LH were similar to those in the follicular phase of normal menstrual cycles in these women. Individual women showed either or both of these patterns of secretion during the period of ovarian suppression post partum. The data suggests that the failure to maintain ovarian follicular development post partum in breast feeding women may be due to: (1) a direct block of LH action at ovarian level, perhaps by the high levels of prolactin associated with lactation and/or (2) an inability of the hypothalamic‐pituitary axis—as a result of the suckling stimulus and/or prolactin—to maintain pulsatile secretion of LH in the face of the negative feedback effects of the increased oestrogen secretion resulting from the initiation of follicular development.
ORAL CONTRACEPTIVE AGENTS DO NOT AFFECT SERUM PROLACTIN IN NORMAL WOMEN
Authors: DAVIS J. R. E. , SELBY C. , JEFFCOATE W. J. 
Published: March 2008

SUMMARYA total of 230 healthy women attending family planning clinics took part in a cross‐sectional study, comparing contraceptive histories and serum prolactin levels. It was found that the distribution histogram of serum prolactin was markedly skewed to the right in all main groups, but that the distribution profile was not affected by use of oestrogen‐containing contraceptives. Neither the dose of oestrogens nor duration of their use affected prolactin levels. We have thus found that currently available combined oral contraceptive agents have no effect on serum prolactin. Analysis of the skewed raw data yields a ‘normal’ range of 110‐700 mU/I, higher than that usually accepted.
PITUITARY AND THYROID INSUFFICIENCY IN THALASSAEMIC HAEMOSIDEROSIS
Authors: LIVADAS D. P. , SOFRONIADOU K. , SOUVATZOGLOU A. , BOUKIS M. , SIAFAKA L. , KOUTRAS D. A. 
Published: March 2008

SUMMARYThyroid and pituitary function tests using hypothalamic releasing factors were performed in seven patients with thalassaemia and secondary haemosiderosis and in a control group of seven healthy subjects. The TSH level in the thalassaemic patients (18.07± 1.10 μU/ml) was higher than in the controls (1.01±0.14 μU/ml, P<0.001). After TRH administration the TSH values increased less than in the controls. Serum thyroxine and FT4I values were lower in the group of patients with thalassaemia (76.7 ± 7.8 nmol/1 and 19.3 ± 2.2) compared to the controls (116.1±6.9 nmol/1, P <0.005 and 38.6 ± 3.6, P <0001). The basal prolactin values did not differ significantly between the two groups, but after TRH administration the increment was significantly lower in thalassaemics than in controls (P <0.005). The basal LH values were lower in the thalassaemic patients (1.37±0.24 ng/ml) than in the controls (3.23 ± 0.50 ng/ml) and did not increase significantly after LHRH administration. The FSH values were also lower in the thalassaemic group (0.46±0.15 ng/ml) compared to the controls (2.06±0.08 ng/ml, p <0.001), and increased only slightly after LHRH administration. We conclude that in thalassaemia pituitary deficiency exists, mostly of gonadotrophs, but possibly also for the thyrotrophs and the lactotrophs. Latent primary hypothyroidism has also been found in the thalassaemic group. The functional abnormalities found in both endocrine glands are best explained as a consequence of coexisting haemosiderosis.