bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monitoring ovarian function by a solid-phase chemiluminescence immunoassay
Authors: Weerasekera D. A. , Kim J. B. , Barnard G. J. , Collins W. P. , Kohen F. , Lindner H. R. 
Published: December 2008

Abstract.
Ovarian function in women may be monitored by a simple, solid-phase, chemiluminescence immunoassay for the measurement of oestrone-3-glucuronide in diluted urine. An IgG fraction of antiserum to oestrone-3-glucuronyl-6-bovine serum albumin is passively adsorbed to the walls of polystyrene tubes. Oestrone-3-glucuronyl-6-aminoethyl-ethyl-isoluminol is the labelled antigen. Daily samples of early morning urine are diluted in buffer (1:100; v/v), and 100 μl removed, in duplicate, for assay. After the binding reaction (1 h at 4°C), the solution is removed by aspiration. The antibody-bound fraction is washed once with buffer (400 μl). Sodium hydroxide (2n, 200 μl) is added and the mixture incubated for 60 min at 22°C. Luminescence is initiated by oxidation of the label with microperoxidase/hydrogen peroxide and the signal integrated for 10s.
An evaluation of the method gave the following values: sensitivity of calibration curve 3.12 ± 0.75 pg/tube (mean ± sd). The intra-assay precision (CV%) was 9.52 (20 replicates; 38.4 ± 3.66 nmol/l) and 8.61 (15 replicates; 102.4 ± 8.82 nmol/l). The inter-assay precision (CV%) was 11.9 (mean of 4 pools−7.03, 23.16, 52.11 and 117.53 nmol/l over 2 months). The mean bias was −0.78% over the range 28 to 448 nmol/l and different aliquots (equivalent to 0.25 to 4 μl) of daily early morning urine gave results that were in good agreement. The concentration (nmol/l; mean ± sd) of oestrone-3-glucuronide in samples of early morning urine collected from healthy women during the early follicular, periovulatory and luteal phases of the menstrual cycle were 40.2 ± 9.9, 102.3 ± 39.4 and 84.3 ± 13.3 nmol/l, respectively. In addition, the results obtained from the analysis of EMU throughout 6 complete menstrual cycles were in good agreement with the values derived by radioimmunoassay (r = 0.94).
The renin-aldosterone system in pre-eclampsia, essential and transient hypertension during pregnancy, and normotensive pregnant and non-pregnant control subjects
Authors: Pedersen E. B. , Rasmussen A. B. , Johannesen P. , Kornerup H. J. , Kristensen S. , Lauritsen J. G. , Wohlert M. 
Published: December 2008

Abstract.
Plasma renin concentration (PRC), plasma aldosterone concentration (PAC), and blood pressure were determined in the third trimester in pregnancy, 5 days and 6 months after delivery in pre-eclampsia, essential and transient hypertension in pregnancy and in normotensive pregnant and non-pregnant control subjects. PRC and PAC were elevated several fold above non-pregnant level in all groups during pregnancy. In pre-eclampsia PRC and PAC were 220 and 160%, respectively, above the levels 6 months after delivery, and thus lower than the corresponding values, 360 and 402%, in normotensive pregnancy. In essential and transient hypertension PRC and PAC increased to the same degree as during normotensive pregnancy. Urinary sodium excretion, serum sodium and creatinine clearance were reduced in pre-eclampsia, but not in essential and transient hypertension when compared to normotensive pregnant controls. All the parameters determined were the same as in non-pregnant controls 6 months after delivery in all groups. There were no correlations between blood pressure and PRC or PAC in any of the groups neither in pregnancy nor after delivery. It is concluded that the renin-aldosterone system is stimulated in lesser degree in pre-eclampsia than in both essential hypertension, transient hypertension and normotensive pregnancy, and there was no evidence for a causal relationship between the renin-aldosterone system and blood pressure neither in normotensive nor hypertensive pregnancy.
Specific binding sites for epidermal growth factor and its effect on human chorionic gonadotrophin secretion by cultured tumour cell lines: comparison between trophoblastic and non-trophoblastic cells
Authors: Hirata Yukio , Sueoka Satoru , Uchihashi Masahito , Yoshimoto Yoshio , Fujita Takuo , Matsukura Shigeru , Motoyama Teiichi 
Published: December 2008

Abstract.
Using human trophoblastic (SCH) and non-trophoblastic (HeLa S3) tumour cell lines, specific binding sites for epidermal growth factor (EGF), a potent stimulator of growth in many tissues, and its effect on secretion of human chorionic gonadotrophin (hCG) and/ or its subunits were compared between these two tumour cells.
Both SCH and HeLa S3 cells possessed two populations of specific binding sites for 125I-labelled EGF: the high affinity (Kd ∼10−10m) and the low affinity (Kd ∼ 7 × 10−10 m) system. Tetradecanoyl phorbol acetate (TPA), a tumour promotor, showed a potent competitor of labelled tracer binding to its receptor sites in both cell lines. EGF stimulated both hCG-α and hCG and/or hCG-β secretion in a dose-responsive manner from SCH cells, whereas it had no effect on hCG-α secretion from HeLa S3 cells. In contrast, dibutyryl cyclic AMP plus theophylline, a phosphodiesterase inhibitor, enhanced hCG-α secretion from both cells, while TPA had no effect in either cells.
These data suggest that EGF may play a physiological role in hCG secretion from trophoblastic tissues and that the mechanism by which hCG and/or its subunits are secreted may differ between trophoblastic and non-trophoblastic tumour cells.
Potentiation by prolactin of the luteotrophic effect of oestradiol in the pregnant rat
Authors: Rodway Richard G. , Garris David R. 
Published: December 2008

Abstract.
The luteotrophic effects of elevated prolactin levels with or without concomitant oestradiol treatment were investigated in the pregnant rat after hysterectomy or hysterectomy plus hypophysectomy. On day 2 of pregnancy, rats were given a single pituitary transplant beneath the renal capsule and were subsequently hysterectomised on day 12. This treatment delayed the next ovulation (as judged by vaginal di-oestrus length) compared to sham-transplanted controls, but did not prevent the fall in serum progesterone concentrations (i.e. luteolysis) resulting from hysterectomy. The administration of 1 or 2 pituitary homo-transplants on day 12 at the time of hysterectomy again prolonged the di-oestrus length but did not prevent subsequent luteolysis. However, daily treatment with 100 μg of oestradiol given to rats which received 2 pituitary transplants on day 2 and which were then hysterectomised on day 12, did result in a maintenance of serum progesterone levels compared to those of oil-treated controls.
In a separate study, pregnant rats were hysterectomised and hypophysectomised on day 12. Administration of either 1 or 2 pituitary transplants failed to maintain luteal function. However, concomitant daily treatment with 100 μg of oestradiol from day 12 onward prevented luteolysis and re-instated the day 12–16 rise in serum progesterone common to the intact pregnant rat. Progesterone levels then declined slowly until the end of the sampling period (day 23). Serum prolactin concentrations rose steadily for the first 10 days after insertion of pituitary transplants on day 12 of pregnancy. These data indicate that prolactin and oestradiol can act synergistically to stimulate progesterone secretion from the rat corpus luteum but only in the absence of the in situ pituitary; the effect is not seen unless hypophysectomy has been performed.
Plasma progesterone levels during long-term treatment with levonorgestrel silastic implants
Authors: Croxatto Horacio B. , Diaz Soledad , Pavez Margarita , Miranda Patricia , Brandeis Astrid 
Published: December 2008

Abstract.
Plasma progesterone levels were measured in 113 women using a subdermal implant containing 200 mg levonorgestrel (NORPLANT™*) in an attempt to assess the roles of anovulation and inadequate luteal function in the contraceptive action of this method. Twenty-two women using an IUD (Copper T 200) served as a control group.
Blood samples were taken twice a week for 6 consecutive weeks. This was done one to four times in each subject during the first 7 years after insertion of NORPLANT. Plasma progesterone was measured by a specific RIA and criteria based upon normal values in this laboratory were used to define each set of samples as ovulatory, uncertain or anovulatory. The rate of anovulation varied between 25 and 80% throughout the 7 years. The highest rate was observed during the first year of treatment. The rate of anovulation was significantly correlated with the plasma levels of levonorgestrel. Varying degrees of inadequate corpus luteum function were detected among NORPLANT users. All sets of samples in the control group were ovulatory and compatible with normal luteal function.
These results clearly show that continuous administration of levonorgestrel by means of NORPLANT interferes with ovulation and/or luteal function in a significant proportion of cycles throughout the first 7 years of use.
Changes in mechanical properties, thermal stability, reducible cross-links and glycosyl-lysines in rat skin induced by corticosteroid treatment
Authors: Oxlund Hans , Sims Trevor , Light Nicholas D. 
Published: December 2008

Abstract.
The effects of systemic cortisol treatment on the biophysical and biochemical properties of skin were investigated. Rats were injected sc with cortisol for 14, 60 and 120 days and samples of lumbar skin were studied.
Corticosteroids exert a biphasic effect on the strength of skin: 1) a relatively fast increase in the strength and stability, caused by an increased collagen cross-linking and 2) an inhibited collagen synthesis which ultimately results in a thinning of the skin and a decrease of collagen content consistent with clinical observations. The thermal stability is increased indicating an increased proportion of thermostable cross-links in skin collagen. No changes are observed in the percentage type III collagen with respect to type I collagen. Increased amounts of glucose attached to the ε-amino group of lysine residues in the collagen are found after long-term treatments, an alteration which may play a role in hampering the tissue functions.
Effects of starvation on circadian variations of plasma TSH in rats
Authors: Hugues J. N. , Reinberg A. , Jordan D. , Sebaoun J. , Modigliani E. , Burger A. G. 
Published: December 2008

Abstract.
Diurnal fluctuations of plasma TSH were investigated in ad libitum fed rats as well as after a 3 day starvation period in order to study the relationship between the circadian pattern of TSH secretion and nutritional status. Our study showed the persistence of a circadian TSH rhythm after a 3 day starvation without any change in the amplitude of plasma TSH variations. However, the 24 h average plasma TSH levels were significantly lower. A suggestive acrophase occurred at the same period of the day in starved and fed rats. Our results suggest that the control of plasma TSH concentrations and nycthemeral rhythm are not closely related and may even possibly be independent of one another.
Somatostatin-28 like immunoreactivity in normal and tumour tissue from duodenum and pancreas
Authors: Ito Seiki , Yamada Yukio , Iwanaga Toshihiko , Kaneko Hiroshi , Shibata Akira 
Published: December 2008

Abstract.
Radioimmunoassay using labelled somatostatin-14 revealed that components of somatostatin-28 antisera cross-reactive to somatostatin-14 were removed by absorption of somatostatin-28 antisera with sepharose 4B-somatostatin-14. Indirect immunofluorescence techniques using specific antisera against somatostatin-28 were carried out in normal pancreas, duodenum, a somatostatinoma in the duodenum, and pancreatic tumour cells containing somatostatin-14 positive cells, in order to establish if somatostatin-28 is present in normal and pathological tissues. Somatostatin-28 like immunoreactivity was present in pancreatic islets cells and in the epithelial cells of the duodenum as well as in the duodenal somatostatinoma and in pancreatic tumour cells. Furthermore, cells reacting with specific antisera against somatostatin-28 were identical to those with somatostatin-14 antisera in normal and pathological tissues. The findings suggested that somatostatin-28 like immunoreactivity may be constantly present in the tissues where somatostatin like immunoreactivity was detected using somatostatin-14 antisera. However, further studies are necessary to clarify whether somatostatin-28 and somatostatin-14 were independently present in these tissues, in other words, whether somatostatin-14 may be produced from somatostatin-28 or not, since somatostatin-14 antisera had cross-reactivities to somatostatin-28.
In vitro conversion of cholesterol into aldosterone and cortisol in different zones of the bovine adrenal cortex
Authors: Karlmar Karl-Eric 
Published: December 2008

Abstract.
The individual steps in the formation of aldosterone and cortisol from cholesterol were assayed in different subcellular preparations from the inner and outer zones of bovine adrenal cortex. In zona glomerulosa the 11β-, 18- and 21-hydroxylase activities were relatively high, whereas the 17α-hydroxylase activity was relatively low. Cholesterol side-chain cleavage and 3β-hydroxysteroid-Δ5-oxidoreductase activity were similar in zona glomerulosa and zona fasciculata-reticularis. The differences were however only quantitative. In no case one specific fraction was totally devoid of enzyme activity. The total content of mitochondrial cytochrome P-450 was relatively high in zona fasciculata-reticularis whereas the content of microsomal cytochrome P-450 was similar in the two fractions. In view of the relatively small differences observed, it seems likely that other factors than distribution of the above enzymes are of major importance for the specific production of gluco- and mineralocorticoids in the two layers.
The preovulatory decline in follicular oestradiol is not required for ovulation in the rabbit
Authors: LeMaire William J. , Janson Per O. , Källfelt Björn J. , Holmes Paul V. , Cajander Stefan , Bjersing Lars , Ahrén Kurt E. B. 
Published: December 2008

Abstract.
Using a method of in vitro perfusion of the rabbit ovary with a chemically defined medium in a recirculation system, normal appearing follicular ruptures occurred following exposure of the ovaries to hCG in vivo (100 IU) or following addition of LH (0.25 μg/ml of NIH B9) to the perfusate. The addition of oestradiol17β (10 μg/ml) to the perfusate did not inhibit these follicular ruptures, although the follicular fluid oestradiol contents were increased more than 100-fold as compared to the control side not receiving the addition of oestradiol. These data suggest that the physiological decline of follicular oestrogen, normally observed in vivo prior to ovulation in the rabbit, is not required as part of the mechanism of ovulation and that normal appearing ovulations can occur even though follicular oestrogen levels are kept artificially elevated.
Synthesis and storage of hormonal granules in cultured cells of the rat pituitary pars intermedia
Authors: Bäck Nils , Hervonen Heikki , Rechardt Leena 
Published: December 2008

Abstract.
Tissue from the pars intermedia of the pituitary from new-born and adult rats was maintained in tissue culture for periods up to 14 days. Both new-born and adult rat pars intermedia cells showed active production of secretory granules during tissue culture, and also showed formaldehyde-chloral induced fluorescence. Immunohistochemically, β-endorphin could be demonstrated in cultured pars intermedia cells.
In contrast to the appearance of the pars intermedia cells in vivo, the granules in the cultured cells were most often seen along the cell membrane, and the cytoplasm was often dominated by clear vacuoles slightly larger than the granules. No exocytotic figures were observed in the cultured cells. The mechanism of hormonal release from the organ, if release does occur, thus remains obscure.
In conclusion, cultured cells from the rat pituitary pars intermedia continue their production of hormonal granules in tissue culture, and thus form a valuable tool for further investigations on the complex regulation of hormonal secretion form the organ.
Role of thyrotrophin-releasing hormone in the development of pituitary-thyroid axis in four anencephalic infants
Authors: Pezzino Vincenzo , Distefano Giuseppe , Belfiore Antonio , Filetti Sebastiano , Mazzone Domenico , Grasso Sebastiano 
Published: December 2008

Abstract.
Anencephaly provides a unique model for studying endocrine functions in absence of hypothalamic influence. We previously reported that in anencephalic newborns both pituitary TSH-secreting cells and the thyroid were normal and were able to function if adequately stimulated. In order to verify if the normal development of the pituitary-thyroid axis in these infants depends on TRH of extrahypothalamic origin, we measured endogenous TRH levels in the clear fluid of a cyst of the cerebro-vasculosa in 4 anencephalic newborns. In these cysts we also injected 200 μg of synthetic TRH and evaluated TSH response in peripheral blood samples.
Endogenous TRH was detectable in the cysts of the cerebro-vasculosa in 3 of the 4 infants. In all 4 cases serum TSH sharply increased after TRH administration. Our data suggest that the normal development of the pituitary-thyroid axis in anencephalic infants either requires no TRH or depends on extrahypothalamic TRH. In this latter case TRH produced by other areas of the central nervous system might be secreted into the cysts of the cerebro-vasculosa, actively transported to the hypophyseal vessels, and might thus reach the pituitary to stimulate TSH-cells growth and function.
Gonadotrophin-secretion in adrenocortical insufficiency: impact of glucocorticoid substitution
Authors: Vierhapper H. , Waldhäusl W. , Nowotny P. 
Published: December 2008

Abstract.
In patients with deficient endogenous glucocorticoid production due to primary adrenal insufficiency (n = 4) or bilateral adrenalectomy (n = 2) a rise in LRH-stimulated concentrations of LH was seen following withdrawal of substitution therapy for 84 h. Consecutive re-administration of glucocorticoids (dexamethasone 2.0 mg/day for 3 days) resulted in increased basal concentrations of LH and FSH and a diminished secretory response of LH upon iv LRH (100 μg). Five patients substituted with glucocorticoids because of adrenocortical insufficiency presented upon the administration of exogenous ACTH1-24 with unchanged basal and LRH-stimulated concentrations of LH and FSH as compared to a placebo experiment. These data suggest that the withdrawal and subsequent re-administration of glucocorticoid substitution alters basal and stimulated concentrations of gonadotrophins in patients with adrenocortical insufficiency, thus providing evidence for the importance of adequate glucocorticoid supply in the regulation of gonadotrophin secretion.
Effect of gonadotrophin-releasing hormone (GnRH) and GnRH agonists upon accumulation of progesterone, cAMP and prostaglandin in isolated preovulatory rat follicles
Authors: Hillensjö Torbjörn , LeMaire William J. , Clark Martin R. , Ahrén Kurt 
Published: December 2008

Abstract.
To study the acute and direct effects of GnRH agonists preovulatory follicles were isolated from PMSG-treated immature rats and incubated for 15–360 min in modified Kreb's bicarbonate buffer. The levels of cAMP, prostaglandin E, and progesterone were analysed in the tissue and/or incubation media. GnRH and two GnRH agonists produced a dose-dependent stimulation of progesterone production with maximal levels 5–6-fold higher than the control group. As compared to LH the magnitude of this effect was small and was detected only after 240–360 min of incubation. GnRH also stimulated prostaglandin E accumulation and this effect was as pronounced as for LH. There were no detectable changes in cAMP levels for any concentration of GnRH when the incubation time varied between 15 and 120 min whether or not a phosphodiesterase inhibitor was present, but after 240 min of incubation a 2-fold incease in cAMP was found. Consistent with previous results, LH caused a pronouced (40–50-fold) increase in follicular cAMP which was already detectable after 15 min of incubation. Indomethacin abolished the rise in prostaglandin E induced either by GnRH or LH but did not affect the response in terms of cAMP or progesterone, and did not affect the stimulation of meiotic maturation of the follicle-enclosed oocytes caused by the hormones. It is concluded that GnRH can exert acute and LH-like stimulatory effects on the preovulatory rat follicle but that the mechanism of GnRH action is different from that of LH.
The effect of prostaglandins in the rat ovary: specific or unspecific stimulation of cAMP, cGMP and progesterone?
Authors: Schindler Hubert , Müller Ulrich , Siebers Jan Willem 
Published: December 2008

Abstract.
Ovarian membranes of the rat do not specifically bind prostaglandin E2 at any stage of development. Attachment of [3H]prostaglandin E2 in the presence of an excess of unlabelled prostaglandin E2 increased in a linear fashion and was not saturable. Prostaglandin E2 stimulated cAMP accumulation by ovarian cells of all developmental stages. This effect was not saturable. An effect of prostaglandin E2 on cGMP levels was not observed. At high concentrations of prostaglandin E2 an increase of ovarian progesterone synthesis was detected. In comparison hCG stimulated progesterone synthesis at much lower concentrations. PGF2α increased cellular and extracellular cAMP at 1000-fold higher concentrations than PGE2 and did not affect cGMP levels.
Imitation of normal plasma growth hormone profile by subcutaneous administration of human growth hormone to growth hormone deficient children
Authors: Christiansen J. Sandahl , Ørskov H. , Binder C. , Kastrup K. W. 
Published: December 2008

Abstract.
The time course of plasma growth hormone (hGH) levels following sc and im injection of hGH was studied in 12 children with growth hormone deficiency who had received long-term treatment with im injections of highly purified hGH. Also the spontaneous diurnal GH levels in 8 normal children of comparable age were recorded.
Blood samples were obtained during 24 h after im and sc injections of 4 IU/m2 hGH and analysed for immunoreactive hGH. While a median peak value of 160 ng/ml (range 135 to 475 ng/ml) was obtained 2 h after im injection, sc injection resulted in a more sustained elevation reaching 41 ng/ml (range 32 to 51 ng/ml) at 6 h subsiding slowly with a median concentration of 15 ng/ml (range 5–24 ng/ml) persisting after 14 h.
Gel chromatography demonstrated that the hGH immunoreactivity of blood samples obtained as late as 14 h after sc injection had unaltered molecular size.
Seven of the patients were further studied after sc injection of 2 IU/m2 at 20.00 h instead of in the morning. A plasma profile was attained during the night which roughly approximated the average nocturnal plasma pattern of the normal children.
Effect of purified somatomedins on thymidine incorporation into lectin-activated human lymphocytes
Authors: Schimpff Rose-Marie , Repellin Anne-Marie , Salvatoni Alessandro , Thieriot-Prevost Geneviève , Chatelain Pierre 
Published: December 2008

Abstract.
These data describe the effects of purified preparations of several growth factors on thymidine incorporation into phyto-haemagglutinin-activated (PHA) human lymphocytes. The somatomedins selected for this study included human somatomedins A and C, insulin-like growth factors (IFG1) and IGF2) and multiplication stimulating activity (MSA). Assays were carried out with and without serum. Complementary assays were performed with a low-molecular serum ultrafiltrate added to somatomedin C and to MSA. We found that all the peptides tested, except MSA, stimulated thymidine incorporation into PHA-activated lymphocytes in a dosedependent manner, even though different doses were required to obtain a response. The data reported point out the multiplicity and the interrelationships of the serum factors involved in the stimulation of human cells growth.