bluuebunny/crossref_metadata_2025_split huggingface dataset:
A SENSITIVE IN VITRO BIOASSAY METHOD FOR LUTEINIZING HORMONE (LH) ACTIVITY
Authors: Van Damme M.-P. , Robertson D. M. , Romaní P. , Diczfalusy E. 
Published: December 2008

ABSTRACT
A specific and sensitive in vitro bioassay method is described for the measurement of LH activity of HCG, HMG and human hypophyseal gonadotrophin (HHG) preparations.
The method is based on the principle that a linear relationship exists between graded doses of HCG, HMG or HHG preparations and the amount of testosterone released into the incubation medium by decapsulated mouse testes.
The sensitivity of the method is 0.4 mIU/ml incubation medium for HCG and 2 mIU/ml for HMG. The useful range of the method is 0.4– mIU/ml for HCG and 2–32 mIU/ml for HMG preparations. A 3 + 3 point design with 6 individual observations per dose is used. Under these experimental conditions the mean index of precision (γ) in 44 assays was 0.22.
All HCG, HMG and HHG preparations yielded parallel dose-effect lines. In the concentrations studied, the assay was not influenced by the presence of FSH, ACTH, STH, LTH, vasopressin, oxytocin and LH releasing hormone activities. The high LH contamination of the highly purified TSH preparations studied precluded an adequate assessment of a possible synergistic or antagonistic effect of TSH on the assay.
REDUCED SENSITIVITY OF THE THYROID TO THYROTROPHIC HORMONE AND LATS FOLLOWING TREATMENT WITH ANTIMICROSOMAL ANTIBODIES
Authors: Földes J. , Takó J. , Bános Cs. , Gesztesi E. , Juhász J. 
Published: December 2008

ABSTRACT
Antibodies raised against the microsomal fraction of the thyroid epithelial cells have been shown to inhibit in vitro binding of LATS to the microsomal fraction and to diminish in vivo thyroid stimulating effects of both LATS and TSH. Antimicrosomal antibody is also likely to block in vivo binding of LATS to the thyroid, and to reduce its rate of elimination from the circulating blood. The results are consistent with the assumption that the receptor structures and site of action of LATS and TSH in the thyroid are identical.
On the basis of these findings the possibility arises that high titres of antimicrosomal antibodies in the serum may interfere with the results of LATS bioassay in such patients. Moreover, it seems reasonable to assume that in Hashimoto's thyroiditis high levels of antimicrosomal antibodies reduce the TSH sensitivity of thyroid, leading to an enhanced secretion of TSH and promoting the development of hypothyroidism.
STIMULATING EFFECT OF DIBUTYRYL CYCLIC ADENOSINE 3′, 5′ MONOPHOSPHATE ON PROTEIN SYNTHESIS IN A THYROIDAL CELL-FREE SYSTEM AT LOW POTASSIUM AND SODIUM CONCENTRATIONS
Authors: Wägar Gustav 
Published: December 2008

ABSTRACT
The aim of the present study was to investigate the effect of dibutyryl cyclic adenosine 3′, 5′ monophosphate (db-cAMP) on the L-14C-leucine incorporation into TCA-precipitable protein in a thyroidal microsomal cell-free system at low cation concentrations. The basic incubation system contained the following cation concentrations: 18 mm K+, 2.5 mm Na+ and 6 mm Mg2+.
Db-cAMP caused a linear stimulation of leucine incorporation in concentrations from 0.5 to 2.5 mm. When the K+ concentration was increased from 18 to 72 mm the stimulating effect of 2.5 mm db-cAMP decreased from 48 to 6 % while the basic incorporation level increased simultaneously. An increase in Na+ from 2.5 to 42.5 mm caused a similar incorporation curve. The optimal concentration of Mg2+ was 6 mm at which concentration the enhancement of leucine incorporation by db-cAMP was most pronounced. Low Ca2+ concentrations did not affect the db-cAMP response. At concentrations over 1 mm, Ca2+ inhibited the protein synthesis without lowering the relative stimulation caused by db-cAMP.
THE INFLUENCE OF CORTISOL ON 2-DEOXYGLUCOSE PENETRATION AND PHOSPHORYLATION BY THE MOUSE EAR STRIP PREPARATION
Authors: Ariyoshi Yutaka , Plager John , Matsui Nobuo 
Published: December 2008

ABSTRACT
The influence of cortisol on 2-deoxyglucose (2-DG) penetration and phosphorylation was studied using the mouse ear strip preparation. The inhibitory effect of cortisol on 2-DG metabolism was first detectable only after a 1 h pre-incubation with cortisol. Cortisol inhibition of 2-DG phosphorylation became evident within 5 min after the addition of 2-G to the incubation medium, a significant inhibition of 2-DG penetration being induced 2 h later. This latter observation is interpreted as reflecting that small differences in intracellular 2-DG between the control and the experimental flasks would be masked by the variation within larger extracellular 2-DG pools during the early time periods. In longer incubation the rate of 2-DG phosphorylation slowed or stopped after 5 h of incubation and hence the increase of intracellular 2-DG accumulation had to be considered. At later time periods, cortisol inhibition of 2-DG penetration became clearly evident. The data are considered to be most consistent with a cortisol effect resulting in a decreased penetration of this sugar through the cell membrane.
BLOCKADE OF THE SURGE OF PROLACTIN AT PRO-OESTRUS BY ADMINISTRATION OF ANTI-OESTROGENIC SUBSTANCE, MER-25
Authors: Yokoyama Akira , Tomogane Hiroshi , Ôta Katuaki 
Published: December 2008

ABSTRACT
A non-steroidal oestrogen antagonist, MER-25, was administered to cycling rats for elucidating the role of oestrogen in the surge of prolactin observed on the afternoon of pro-oestrus (POe).
In animals injected with 20 mg of MER-25 intramuscularly on the afternoon (16.30 h) of the first day of dioestrus (D-1), the surge of prolactin was blocked while the level of prolactin on the afternoon of POe of these animals was significantly higher than that of the corresponding controls injected with oil. Ovulation was also blocked in these animals treated with the drug on the afternoon of D-l. On the other hand, treatment on the morning (10.30 h) of the 2nd day of dioestrus failed to prevent not only the surge of prolactin but also ovulation.
These observations provide strong evidence for the view that oestrogen is responsible for the surge of prolactin on the afternoon of POe, and that the surge is accompanied by that of LH.
BIOTRANSFORMATION OF PREGNENOLONE AND PROGESTERONE BY RABBIT OVARIAN FOLLICLES AND CORPORA LUTEA
Authors: YoungLai Edward V. 
Published: December 2008

ABSTRACT
Rabbit ovarian follicles obtained prior to and after mating and corpora lutea (24 h and 48 h post-coitus) were incubated with radioactive pregnenolone and progesterone to determine whether these substrates could serve as precursors of androgens and oestrogens. Incubations were carried out for 3 h in Hanks balanced salt solution: medium 199: normal rabbit serum: 55:30:15. Granulosa cells and corpora lutea converted pregnenolone to progesterone but no labelled oestrogens could be detected. Trace amounts of androgens were synthesized by the granulosa cells. Whole sliced follicles and theca formed progesterone from pregnenolone and androgens from both substrates. Oestradiol-17β was only synthesized by the whole sliced follicles and in one experiment by theca cells. Mating caused an increase in the 3β-hydroxysteroid dehydrogenase for pregnenolone and formation of testosterone but no oestrogens by the theca cells. These results indicate that both theca interna and granulosa cells are needed for oestrogen biosynthesis by rabbit follicles.
BIOLOGICAL ACTIVITY OF SYNTHETIC HUMAN CORTICOTROPHIN WITH REVISED AMINO ACID SEQUENCE
Authors: Schenkel-Hulliger Lotte , Maier René , Barthe Pierre L. , Desaulles Pierre A. , Jarret Andrée , Riniker Bernhard , Rittel Werner , Sieber Peter 
Published: December 2008

ABSTRACT
The corticotrophic, melanotrophic and lipolytic activity of synthetic human corticotrophin of revised structure has been evaluated and compared with that of synthetic porcine ACTH (uncorrected structure). The amino acid sequence of the two peptides differs at 3 sites in the 25 to 31 region. The two peptides exihibit identical biological activities in in vitro and in vivo test systems in the rat.
IMMUNOREACTIVE GROWTH HORMONE IN PLASMA AND URINE IN JUVENILE DIABETICS BEFORE AND DURING INITIAL INSULIN TREATMENT
Authors: Hanssen Kristian F. 
Published: December 2008

ABSTRACT
Twenty newly diagnosed, but as yet untreated patients of both sexes with classical juvenile diabetes were investigated by determining the mean plasma immunoreactive growth hormone (IRHGH) and urinary IRHGH for a 24 hour period before and during initial insulin treatment.
The plasma IRHGH was significantly higher (0.05 > P > 0.01) before than during initial insulin treatment. During initial insulin treatment, the mean plasma IRHGH was significantly higher (0.01 > P > 0.001) than in a control group. The urinary IRHGH was significantly higher (0.01 > P > 0.001) before than during insulin treatment. The increased urinary IRHGH observed before insulin treatment is thought to be partly due to a defective renal tubular reabsorption of growth hormone. No significant correlation was found between the mean blood sugar and plasma or urinary IRHGH either before or during insulin treatment.
INSULIN RESPONSE TO GLUCOSE INFUSION DURING PREGNANCY. A PROSPECTIVE STUDY OF HIGH AND LOW INSULIN RESPONDERS WITH NORMAL CARBOHYDRATE TOLERANCE
Authors: Edström Karin , Cerasi Erol , Luft Rolf 
Published: December 2008

ABSTRACT
A decreased insulin response to glucose administration has been suggested to be a prerequisite for the development of diabetes mellitus. Factors that increase the demand for insulin in the organism may precipitate diabetes in subjects with a low insulin response to a glucose infusion test (GIT). Since it is well-known that pregnancy is a diabetogenic factor, its effect on the carbohydrate metabolism of subjects with a low insulin response was studied.
During pregnancy, the insulin response of the low responders was enhanced as in the controls, but at all stages the insulin response was significantly less than in the controls. None of the subjects developed glucose intolerance during pregnancy. The fasting blood glucose and plasma insulin levels and the k-value in intravenous glucose tolerance tests (IVGTT) were modified according to similar patterns in both groups. The sensitivity to endogenous insulin was significantly greater in the low insulin responders but was reduced to a greater extent than in the controls towards the end of pregnancy.
In four of the 11 low insulin responders the initial insulin response to glucose in the last trimester was lower than in mid-pregnancy. This occurred only in one out of 14 high insulin responders.
It is suggested that gestational diabetes occurs in those low insulin responders who demonstrate either a dramatic decrease in insulin sensitivity, or limitations in the enhancement of insulin release, or, more likely both conditions.
CORTISOL BINDING CAPACITY IN PLASMA DURING ANAESTHESIA AND SURGERY
Authors: Kehlet Henrik , Binder Christian , Engbæk Christen 
Published: December 2008

ABSTRACT
The transcortin binding capacity and cortisol binding to albumin were determined before and after induction of anaesthesia and also post-operatively in 14 normal subjects undergoing major surgery. Plasma non-protein-bound (free) cortisol and total cortisol in the plasma were measured by an ultrafiltration technique and a competetive protein-binding technique, respectively.
The results showed that the anaesthetics caused a decreased (0.05 < P < 0.1) binding of cortisol to albumin, while the transcortin binding capacity was unchanged. Post-operatively the mean transcortin binding capacity decreased from 24.6 to 20.4 μg cortisol per 100 ml (P < 0.01) and the cortisol binding to albumin returned to pre-anaesthetic values. These findings could not be related to changes in the concentration of albumin, α2-protein and total protein in plasma.
HYPERRESPONSIVENESS TO LYSINE-VASOPRESSIN IN CUSHING'S DISEASE
Authors: Coslovsky Rafael , Wajchenberg Bernardo Léo , Nogueira Otilia 
Published: December 2008

ABSTRACT
The lysine-8-vasopressin (LVP)-test was performed in 11 normal subjects, with pituitary-dependent Cushing's disease and in 3 cases of Cushing's syndrome due to an adrenocortical carcinoma. The plasma 17-hydroxycorticosteroids response to LVP in Cushing's disease was compared with the response of the normal controls. It is concluded that patients with pituitary-dependent Cushing's syndrome are hyper-responsive to LVP. The possible mechanisms of this hyper-responsiveness are discussed: release of ACTH from the pituitary and/or an increased release of cortisol from the hyperplastic adrenals may occur. As expected, patients with Cushing's syndrome due to an adrenocortical carcinoma did not respond to LVP.
It is suggested that the LVP-test can be used for the diagnosis of Cushing's syndrome and for the differential diagnosis between Cushing's disease and Cushing's syndrome due to an adrenocortical carcinoma, although it is recognized that in some cases this test will not be adequate.
CONJUGATION OF 16-EPIOESTRIOL BY PREGNANT WOMEN
Authors: la Torre B. de , Wiqvist N. , Diczfalusy E. 
Published: December 2008

ABSTRACT
[4-14C,16α-3H]16-Epioestriol (1,3,5(10)-oestratriene-3,16β,17β-triol) has been synthesized and tracer amounts were administered to two women in the form of an intravenous infusion two days prior to the interruption of gestation. Various conjugated forms of 16-epioestriol were isolated and identified by their conversion into the completely methylated derivatives, subsequent hydrolysis and crystallization to constant isotopic ratio. The quantitatively most important conjugate was the 16-glucosiduronate, followed by the 3,16-diglucosiduronate and the 3-sulphate,16-glucosiduronate. No 3-glucosiduronate or 3-sulphate was isolated. There was a changing pattern of conjugation with time: during the first six hours of urine collection the 16-glucosiduronate was predominant, whereas during the subsequent six hours the 3,16-glucosiduronate was the quantitatively most important conjugate.
Part of the administered 16-epioestriol was recovered from each urine specimen in the form of oestriol.
AN IMPROVED TECHNIQUE FOR MEASURING SOMATOMEDIN ACTIVITY IN VITRO
Authors: Van den Brande J. L. , Caju M. V. L. Du 
Published: December 2008

ABSTRACT
A method for measuring somatomedin activity in vitro is described. Porcine costal cartilage fragments are prepared and incubated using a special dissection and incubation apparatus. The schedule consists of a 24 h pre-incubation, 46 h of incubation with the test substance and 3 h of post-incubation in a medium containing both 35S-Na2SO4 and 3H-thymidine. The average index of precision is 0.15 for 35S-uptake and 0.19 for 3H-thymidine. Although the assay is less sensitive than the hypophysectomized rat assay, it yields a considerable increase in precision, it is far less laborious to perform and is not so expensive.
A COMPARATIVE STUDY OF DEHYDROEPIANDROSTERONE AND DEHYDROEPIANDROSTERONE SULPHATE DYNAMICS BY THE "URINARY" AND "BLOOD APPROACH" UNDER PHYSIOLOGICAL CONDITIONS
Authors: Fehér T. , Halmy L. 
Published: December 2008

ABSTRACT
The dynamic parameters of dehydroepiandrosterone and dehydroepiandrosterone sulphate metabolism have been determined following a single injection of [4-14C] dehydroepiandrosterone and [7α-3H] dehydroepiandrosterone sulphate into normal female subjects. The urinary secretion and production rates, the ϱDDS and ϱDSD conversion factors, the metabolic clearance rates, blood production rates and distribution volumes were calculated. Although the comparison between urinary and blood parameters of steroid dynamics suggested certain limitations of the methods used, they were found suitable for gaining information on dehydroepiandrosterone and dehydroepiandrosterone sulphate metabolism. A poor extra-adrenal conversion of dehydroepiandrosterone to the sulphate, small dehydroepiandrosterone sulphate and large dehydroepiandrosterone distribution volumes or clearance patterns, and a possible correlation between the blood parameters of dehydroepiandrosterone sulphate and anthropomorphology of normal female subjects were found.
ACCENTUATION BY ANGIOTENSIN II OF THE ANTIDIURETIC AND DIPSOGENIC RESPONSES TO INTRACAROTID INFUSIONS OF NaCl AND FRUCTOSE
Authors: Olsson Kerstin , Kolmodin Rigmor 
Published: December 2008

ABSTRACT
Infusions of angiotensin II (angiotensin) into the lateral cerebral ventricle of hydrated goats were made alone, or in combination with intracarotid infusions of hypertonic NaCl. The dose of angiotensin used (0.3 ng/kg min) had negligible antidiuretic, and no dipsogenic effect of its own. However, it markedly potentiated the antidiuretic hormone (ADH) releasing effect of intracarotid infusions of hypertonic NaCl, and made these infusions become dipsogenic.
When angiotensin was infused together with hypertonic NaCl into the carotid artery, a 15 times higher dose had to be administered to obtain a comparable degree of potentiation. The results confirm that Na+ and angiotensin interact in the central control of water balance and support the view that receptors sensitive to changes in the Na+ concentration of the cerebrospinal fluid play a role in this control.
When infused into the carotid artery together with hypertonic fructose, angiotensin also enhanced the ADH-releasing effect of the fructose infusions. If this reflects a central sodium-angiotensin interaction, it would indicate that the intracarotid infusion of hypertonic fructose affects the formation of cerebrospinal fluid in such a manner as to cause a rise in its Na+ concentration.
IN VITRO METABOLISM OF STEROID HORMONES BY CHICKEN BRAIN
Authors: Nakamura Takao , Tanabe Yuichi 
Published: December 2008

ABSTRACT
The brains of 14-month-old White Leghorn cocks were homogenized, fractionated by differential centrifugation, and used as enzymatic materials. When [4-14C]pregnenolone was incubated with the brain homogenate, the substrate was recovered without conversion. After incubation of [4-14C] progesterone with the brain homogenate, it was converted to 5α-pregnanedione and 3α-hydroxy-5α-pregnan-20-one. When [4-14C]17α-hydroxyprogesterone was incubated with the brain homogenate, it was metabolized to androstenedione, 3α, 17α-dihydroxy-5α-pregnan-20-one and 17α,20α-dihydroxy-4-pregnen-3-one. [4-14C] Androstenedione was metabolized to 5α-androstanedione, testosterone, androsterone, epiandrosterone and 5α-androstanediol; and [4-14C]testosterone was metabolized to androstenedione, 5β-dihydrotestosterone and 5β-androstanediol in the chicken brain. The enzymatic pattern in the brain of cocks was characterized by high activities of the 17β-hydroxysteroid dehydrogenase. Δ4-5β- and Δ5-5β-hydrogenase which acted on both C19- and C21-steroids, but was lacking in Δ5-3β-hydroxysteroid dehydrogenase associated with the Δ5a-Δ4isomerase, and 17α-hydroxylase.
LH-RH TEST IN 100 PATIENTS WITH OVARIAN INSUFFICIENCY
Authors: Czygan P.-J. , Breckwoldt M. , Lehmann F. , Langefeld R. , Bettendorf G. 
Published: December 2008

ABSTRACT
The effect of synthetic LH-RH was studied in 100 patients with various types of ovarian insufficiency by following up the FSH- and LH-levels in plasma. LH-RH was administered in doses of 12.5, 25 and 100 μg as a rapid intravenous injection. The patients were classified according to the endocrine state of the pituitary as evidenced by the urinary gonadotrophin levels. A clear correlation between the functional state of the pituitary and its responsiveness to exogenous LH-RH was demonstrated. Most of the patients with undetectable low urinary gonadotrophin levels failed to respond. The majority of patients with gonadotrophin excretion in the normal range and those with elevated levels reacted with a dose dependent increase in circulating LH. The amount of liberated FSH however was related to the injected dose only in patients with high gonadotrophic excretion.
The present study indicates that synthetic LH-RH provides a useful tool in the evaluation of the pitutiary function particularly in patients with low and with undetectable gonadotrophin excretion. The data presented in this paper also demonstrate that the functional state of the pituitary is clearly reflected by the urinary gonadotrophin levels.
THE DEVELOPMENT OF AN IN VITRO SYSTEM FOR ESTIMATING OXYTOCINASE IN THE RABBIT HYPOTHALAMUS AND THE EFFECTS OF SOME PROTEIN SYNTHESIS INHIBITORS AND OESTRADIOL-17β ON ENZYME ACTIVITY
Authors: Frith Dona A. , Hooper K. C. 
Published: December 2008

ABSTRACT
An in vitro system for investigating the effects of steroid hormones and protein synthesis inhibitors on hypothalamic peptidases inactivating oxytocin has been developed.
In the presence of oestradiol-17β enzyme activity was increased in the in vitro system whilst this increase was blocked completely by cycloheximide and partially blocked by actinomycin-D. It is apparent therefore that oestradiol-17β acts directly on the hypothalamus stimulating oxytocinase activity.
RAPID ESTIMATION OF HUMAN CHORIONIC SOMATOMAMMOTROPHIN (HCS) BY HAEMAGGLUTINATION INHIBITION AND COMPARISON OF RESULTS WITH RADIOIMMUNOASSAY
Authors: Spona J. , Töpert M. 
Published: December 2008

ABSTRACT
A method of haemagglutination inhibition assay of HCS was developed utilizing formaldehyde and glutaraldehyde to conjugate the hormone to sheep red blood cells. This technique is sufficiently sensitive (8.7 ng/ml) so that assay of HCS from early pregnancy serum (17 weeks of gestation) can be performed directly after 1:50 dilution. Results can be obtained within 3 h. HCS sensitized red blood cells were shown to be stable for several months.
HCS levels of 20 normal pregnancies were estimated throughout gestation. Forty-two sera from pregnant subjects were assayed by this technique and radioimmunoassay (RIA). The values obtained by the 2 methods had excellent correlation (r = 0.95). Reproducibility of the present method was ± 15 %. Data of HCS serum levels obtained by the present technique and by RIA in high-risk pregnancies are compared and the conclusion is reached that any of these techniques can be used for the successful clinical assay of HCS.
THE TRANSPLACENTAL PASSAGE OF THYROXINE AND FOETAL THYROID FUNCTION IN THE RAT
Authors: Gray Barry , Galton Valerie Anne 
Published: December 2008

ABSTRACT
A study has been made of the transplacental passage of thyroxine (T4) in rats when the hormone is present in physiological concentrations, and of the activity of the foetal thyroid gland in the perinatal period. Several aspects of foetal thyroid function were assessed in intact and thyroid-ectomized (TX) pregnant rats maintained with graded doses of T4. A daily dose of 2 μg T4/100 g body weight yielded near normal maternal and foetal serum PBI levels; with a dose of 1 μg the values were slightly low. Both these doses resulted in a decrease in the total and T4 iodine content of the foetal thyroid; an even greater decrease occurred in rats maintained with 5 μg/100 g body weight/day. The rate of uptake of iodine by the foetal gland was significantly depressed by the 2 but not the 1 μg dose. Serum PBI levels in the foetus were related directly to the dose of T4 and inversely with the degree of depression of the thyroid gland. Both maternal and foetal serum PBI levels in the unsupplemented TX rats were at least 60 % of normal and there was evidence of increased secretion of T4 by the foetal thyroid. The data indicate that the placenta is readily permeable to T4 when the hormone is present in maternal serum in doses that are close to physiological. However it was not possible to estimate the extent of the placental transfer of endogenous hormone. Significant foetal thyroid function was evident near term. It is suggested that both the foetal and maternal thyroids contribute to the maintenance of serum T4 levels in the foetus.