bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of catecholamines in estradiol and progesterone secretion by cultured explants and cells of human term placentae
Authors: Barnea Eytan R. , Perlman Rina , Fakih Hassan , Bick Tova , Kol Shahar , Hochberg Zeev 
Published: December 2008

Abstract.
The effects of physiological concentrations of the native catecholamines norepinephrine and epinephrine upon term placental hormonal function were examined by measuring estradiol and progesterone secretion by organ and cell culture systems. Results show that, in explants, both catecholamines caused a significant increase in the secretion of both sex steroids, p < 0.05. Estradiol secretion was blocked by the alpha and beta adrenergic receptors antagonists, phenoxybenzamine and propranolol, respectively, p < 0.05. Norepinephrine but not epinephrine dependent progesterone secretion was blocked by propranolol. In cells, epinephrine stimulated cyclic AMP generation and caused a 30% increase in estradiol secretion, p < 0.05. Both were abrogated by propranolol. Norepinephrine increased secretion by 25%, p < 0.05. This was inhibited by yohimbin and prazosin, alpha-1 and -2 receptors antagonists, respectively. In conclusion, the placenta in vitro is a target organ for catecholamines. The marked response of the explant system as compared with the marginal response of the cell culture system indicates that cell to cell contact/communication is required for full expression of catecholamine effect.
Effect of gonadectomy on growth hormone, IGF-I and sex steroids in children with complete and incomplete androgen insensitivity
Authors: Cicognani Alessandro , Cacciari Emanuele , Tacconi Moreno , Pascucci Maria G. , Tonioli Susanna , Pirazzoli Piero , Balsamo Antonio 
Published: December 2008

Abstract.
IGF-I, testosterone and estradiol levels were evaluated in 8 girls with androgen insensitivity immediately before and from 1 to 3 months after bilateral gonadectomy. In 6 patients GH secretion was evaluated before and after gonadectomy by means of an arginine test and in 3 a sleep test was also performed. Mean IGF-I level before surgery was significantly higher than that of normal controls (2850 ± 1230 vs 1680 ± 1040 U/l, p < 0.025). After gonadectomy a significant decrease was evident for testosterone, estradiol and IGF-I levels. A positive correlation between IGF-I and estradiol levels was present before surgery (p < 0.005). The presence of a correlation with estradiol, but not with testosterone, and the knowledge that this syndrome is due to an insensitivity to androgens, but not to estradiol, support the hypothesis that the estradiol level is the major determinant for the control of IGF-I values in these patients. After gonadectomy, a substantial decrease of the 12-h nocturnal GH secretion was evident. Comparison of the nocturnal GH levels before surgery of the 3 patients with those of normal subjects of the same age showed hormonal values higher than 1 sd over the mean values of control subjects. Even if the number of patients studied is too small to draw any definitive conclusion, these data may suggest that sex hormones play a role in the control of IGF-I levels, a function which seems to be mediated through GH secretion.
Changes of blood flow in the adenohypophysis of normal and estrogen pretreated Fisher rats by tamoxifen
Authors: Stawowy Andrzej , Kemeny Andras A. , Jakubowski Jan 
Published: December 2008

Abstract.
Blood flow was measured in the adenohypophysis and in the cerebral cortex of female F344 rats over a period of 90 min using the hydrogen clearance method. Tamoxifen, 1 mg/kg, administered iv reduced the blood flow in the adenohypophysis by 35%, whereas cerebral blood flow and arterial pressure remained unchanged. Seven days sc treatment with tamoxifen (1 mg/kg daily) had no demonstrable effect on blood flow. Anterior pituitary hyperplasia was induced in 15 rats with diethylstilbestrol containing implants. These rats responded to 7 days of sc tamoxifen treatment by 30% increase in adenohypophyseal blood flow. These results suggest that tamoxifen has a different effect on adenohypophysial circulation of the rat depending on whether it is administered in a low- or high-estrogen state.
Controlled release of a GnRH agonist from a polyhydroxybutyric acid implant: reversible suppression of the menstrual cycle in the macaque
Authors: Fraser H. M , Sandow J. , Seidel H. R. , Lunn S. F. 
Published: December 2008

Abstract.
The use of polyhydroxybutyric acid as a matrix for delivery of the GnRH agonist buserelin was studied in adult stumptailed macaques with regular menstrual cycles. This material contained 5.0 mg buserelin in a disk of 0.6 cm diameter and 0.15 cm thickness. The effects on pituitary-ovarian function were examined and buserelin release profiles from 30000 and 150000 molecular weight polyhydroxybutyric acid matrices were compared. In an attempt to reduce the high initial release rate of buserelin from these disks, and to prolong the effective period of release, implants of 30 000 molecular weight were coated with cyanoacrylate. The implants were removed after 28, 35 or 42 days for the 30000, the 150000 and the coated implants, respectively. The urinary excretion profile for the agonist revealed a high initial release of buserelin from these implants followed by a rapid decline. The coated disks released significantly less (p < 0.05) buserelin over the first 3 days than did either of the uncoated implants, but maintained release of the agonist over a longer period. Inhibition of ovulation and suppression of estradiol secretion lasted for the duration of treatment in 3 of 5 macaques receiving the 30000 implant, and in 5 of 5 receiving the 150000 or the coated implant. In 3 macaques in whom the coated implant was left in situ, ovulation was suppressed for 104 ± 3.7 days. These results demonstrate that a polyhydroxybutyric acid matrix can be used as a depot formulation for a GnRH agonist and that improved control of release of the agonist can be achieved by coating such implants with cyanoacrylate. This approach may be useful in experimental and clinical situations and may be applicable for delivery of other peptide hormones.
Azathioprine in the treatment of thyroid-associated ophthalmopathy
Authors: Perros Petros , Weightman David R. , Crombie Alex L. , Kendall-Taylor Pat 
Published: December 2008

Abstract
Azathioprine is used in the treatment of thyroid-associated ophthalmopathy, but its effectiveness has not been evaluated. In the present study 20 patients with moderately severe ophthalmopathy were recruited; 10 patients received azathioprine and the other 10 matched patients served as controls. During the treatment period (lasting 1 year) and 1 year later, no changes were detected in exophthalmometer readings, visual acuity or measurement of palpebral aperture. Differential intraocular pressure fell with time in both groups. Azathioprine treatment did not significantly influence these parameters, although it did induce significant decrease in thyroid microsomal antibodies and in thyroid-stimulating hormone binding inhibiting immunoglobulin index. The study demonstrates that thyroid-associated ophthalmopathy of moderate severity, often improves with time without treatment. Azathioprine is not an effective treatment for patients with moderately severe thyroid-associated ophthalmopathy. The study emphasises the necessity for an adequately matched control population in the evaluation of therapy.
Triiodothyronine autoantibodies in Graves' disease: Their changes after antithyroid therapy and relationship with the thyroglobulin antibodies
Authors: Wang Pei-Wen , Huang Miau-Ju , Liu Rue-Tsuan , Chen Chung Dar 
Published: December 2008

Abstract.
Sera of 63 patients with Graves' disease, and 49 control subjects were assayed for T3 autoantibodies by a sensitive radioimmunoassay after being stripped of the endogenous thyroid hormone. T3 autoantibodies were demonstrated in 27% of patients with Graves' disease. After antithyroid treatment, T3 autoantibodies in 75% of the patients with positive antibody before therapy changed to negative titre during a follow-up period of 1 to 12 months. Also, a significant decrease of T3 autoantibodies was observed at 1 month after therapy in all patients who received antithyroid treatment. A further study of T3 autoantibodies and anti-thyroglobulin antibodies showed that the latter were demonstrated in 100% of patients with positive T3 autoantibodies and that T3 autoantibodies existed in about one third of patients with positive anti-thyroglobulin antibodies. The results suggested that T3 autoantibodies could be a subpopulation of the heterogenous anti-thyroglobulin antibodies. Although the fall of T3 autoantibodies in some patients was correlated to that of anti-thyroglobulin antibodies, the overall correlation between T3 autoantibodies and anti-thyroglobulin antibodies was poor. In conclusion: 1. T3 autoantibodies may be suppressed by antithyroid drugs. 2. Being a subpopulation of anti-thyroglobulin antibodies, T3 autoantibodies may be caused by an antigenic site within the big thyroglobulin molecule, whereas their titre was not correlated with that of the overall heterogenous anti-thyroglobulin antibodies.
Effects of central osmotic stimulation on vasopressin and enkephalin release into the blood and cerebrospinal fluid and blood pressure
Authors: Ota Kozo , Kimura Tokihisa , Matsui Kuniaki , Iitake Kazuhiro , Shoji Masaru , Inoue Minoru , Sato Kazutoshi , Ohta Masahiro , Yamamoto Tadasu , Yoshinaga Kaoru 
Published: December 2008

Abstract
To assess the central effect of hypertonic NaCl on the release of vasopressin (AVP) and methionine enkephalin-like substances into the blood and cerebrospinal fluid, and on blood pressure, ventriculocisternal perfusion (0.25 ml/min, 60 min) was performed in anesthetized dogs with artificial cerebrospinal fluid (CSF), either isotonic (300 mosmol/kg) or hypertonic (600 and 1200 mosmol/kg). The effect of central administration of a V1-AVP antagonist on the central osmotic challenge was also studied. In dogs, given 600 mosmol/kg, CSF osmolality increased with a concomitant rise in mean arterial pressure and plasma AVP concentrations. Plasma osmolality, heart rate, CSF AVP and plasma and CSF methionine enkephalin-like substances showed no significant change. In dogs, given 1200 mosmol/kg, the CSF osmolality increase was accompanied by a rise in mean arterial pressure, heart rate, plasma AVP and CSF AVP. Plasma osmolality and plasma and CSF methionine-enkephalinlike substances did not change significantly. A V1-AVP antagonist given centrally attenuated the rise in mean arterial pressure induced by osmotic challenge. In dogs, given 300 mosmol/kg, no parameters changed significantly except for a gradual fall in heart rate. These results suggest that central osmotic stimulation by hypertonic NaCl increases blood pressure, heart rate and the release of AVP, but not methionine enkepholin-like substances, into the blood and CSF, and a V1-blocker given centrally attenuates the pressor response.
Evaluation of the pituitary-adrenal axis before, during and after pituitary adenomectomy. Is perioperative glucocorticoid therapy necessary?
Authors: García-Luna Pedro P. , Leal-Cerro Alfonso , Rocha José L. , Trujillo Francisco , Garcia-Pesquera Felipe , Astorga Ricardo 
Published: December 2008

Abstract
Under the supposition that ACTH secretion will be compromised by surgical trauma, patients with pituitary adenomas undergoing transsphenoidal adenomectomy are frequently given corticoids, even though this therapy is controversial. We studied 10 patients with pituitary adenomas whose adrenocortical function was sufficient prior to surgery. The ACTH and cortisol levels rose significantly during surgery in all of these patients. Five patients completed a two-year postoperative follow-up period and their ACTH and cortisol values remained within normal limits. It may be that patients undergoing transsphenoidal surgery for pituitary adenomas do not need perioperative glucocorticoid treatment, since the hypophyseal-adrenal axis does retain its integrity.
A polyclonal antiserum against chromogranin A and B - a new sensitive marker for neuroendocrine tumours
Authors: Eriksson B. , Arnberg H. , Öberg K. , Hellman U. , Lundqvist G. , Wernstedt C. , Wilander E. 
Published: December 2008

Abstract
Chromogranins A, B, and C, proteins that are co-stored and co-released with peptides and amines, have been identified in a variety of neuroendocrine tissues, both normal and neoplastic. We examined the secretion of chromogranin A and chromogranin A + B by hormone-producing tumours in patients with endocrine pancreatic tumours, carcinoid tumours, pheochromocytomas, and small cell lung cancer. The radioimmunoassay determining the plasma concentrations of chromogranin A + B showed a greater sensitivity than that determining chromogranin A alone. All patients with endocrine pancreatic tumours, carcinoids, and pheochromocytomas had increased levels of chromograin A + B, whereas a small number of the patients (5/18 with endocrine pancreatic tumours and ⅓ with pheochromocytomas) had normal levels of chromogranin A. Also in immunocytochemical stainings, our polyclonal antiserum detecting both chromogranin A and B showed a greater sensitivity than other available antisera against chromogranin A, B and C. We have demonstrated that a polyclonal antiserum against a mixture of chromogranin A and B might be a more sensitive marker than chromogranin A alone for diagnosing neuroendocrine tumours. This is not surprising, since both chromogranins are widely distributed in neuroendocrine cells.
Metabolic fuel and amino acid transport into the brain in experimental hypothyroidism
Authors: Mooradian Arshag D. 
Published: December 2008

Abstract
The effect of hypothyroidism in the adult rat on blood-brain barrier and muscle transport of hexoses, neutral amino acids, basic amino acids, monocarboxylic acids, and ketone bodies was examined using single arterial injection-tissue sampling technique. The cerebral blood flow and brain extraction of 3H2O (internal reference substance) was not altered in 3-month-old hypothyroid rats maintained on methimazole, 0.025% in the drinking water, for 7 weeks. The brain uptake index of D-β-hydroxybutyrate was significantly reduced in hypothyroid rats (2.4 ± 0.3 vs 4.6 ± 0.6% p<0.001). Hypothyroid rats given thyroid hormone replacement therapy had normal brain uptake of D-β-hydroxybutyrate (4.4 ± 0.8%). The brain uptake index of butyrate was also significantly reduced in hypothyroid rats (39.3 ± 2.1 vs 47.2 ± 0.74%, p<0.001). The brain uptake index of other test substances and muscle uptake of nutrients examined were not altered in hypothyroid rats. These studies indicate that of the four transport systems examined in two tissues, the blood-brain barrier monocarboxylic acid transport system is most susceptible to the hypothyroidism-induced changes.
Interleukin 6 possibly induced by interleukin 1β in the pituitary gland stimulates the release of gonadotropins and prolactin
Authors: Yamaguchi Masaaki , Matsuzaki Noboru , Hirota Kenji , Miyake Akira , Tanizawa Osamu 
Published: December 2008

Abstract
The abilities of recombinant human interleukin 1 (IL-1) and IL-6 to induce release of FSH, LH and PRL from rat pituitary cells in vitro were examined. IL-1 and IL-6 induced significant releases of FSH, LH and PRL within 3 h. The extents of release of these compounds induced by IL-1 and IL-6 were similar to those induced by GnRH and TRH. Rat anterior pituitary cells released IL-6 spontaneously, and its release was enhanced by IL-1β. This effect of IL-1β was inhibited significantly by a rabbit anti-IL-1β antiserum. These findings suggest that IL-1 induced the release of IL-6 from rat pituitary, and that the released IL-6 stimulated the secretions of FSH, LH and PRL.
Effects of parathyroid hormone fragments on the growth of murine mandibular condylar cartilage in vitro
Authors: Shurtz-Swirski Revital , Lewinson Dina , Shenzer Pesia , Mayer Hubert , Silbermann Michael 
Published: December 2008

Abstract
The present study showed that the fragment hPTH (1–34) is mitogenic in organ cultures of neonatal mandibular condylar cartilage, and even more so in late fetal condyles. Three fragments of hPTH were used to clarify which part of the molecule possesses a mitogenic effect alike that of the native hormone: hPTH (1–34), (28–48) and (53–84). [3H]thymidine incorporation into trichloracetic acid insoluble material and quantitative autoradiography were employed in a serum-free medium to assess the effects of these fragments while light and electron microscopy studies served for morphological evaluations. It became evident that the fragment hPTH (1–34) enhanced the incorporation of [3H]thymidine, a fact that could be noted only in serum-free medium. The putative target cells for the effects of hPTH (1–34) were the chondroporogenitor cells which also appeared to have experienced a blockage in their differentiation into chondroblasts. Ultrastructurally, the latter cells responded in the formation of adherent profiles of plasma membranes, whereas the differentiated zone of the cartilage reduced its size. Using serum-free medium, hPTH (1–34) also brought about an inhibition in alkaline phosphatase activity, a fact that was not encountered in medium containing serum. By contrast, hPTH (28–48) had no mitogenic effect, although treated specimens revealed morphological changes in the chondroprogenitor cell zone along with an enhancement of cartilage cells hypertrophy. No significant effects on either mitogenecity or morphology could be noted in hPTH (53–84)-treated cultures.
Characterization of dimeric forms of human pituitary growth hormone by bioassay, radioreceptor assay, and radioimmunoassay
Authors: Brostedt Peter , Luthman Marguerite , Wide Leif , Werner Sigbritt , Roos Paul 
Published: December 2008

Abstract
Seven highly purified dimeric forms of human pituitary growth hormone, composed of the monomeric forms 20 K hGH, 22 K hGH and 24 K hGH linked together by noncovalent or covalent bonds, have been characterized by an in vitro bioassay (the Nb2 assay), a radioreceptor assay and a radioimmunoassay. Considerable differences in the ability to displace labelled recombinant hGH were observed in the radioreceptor assay. The seven dimeric forms varied over a range between 22 K hGH (most effective) and 20 K hGH. The three covalently-linked dimeric forms had nearly identical affinity constants. The mitogenic action of all but one of the hGH dimers in the Nb2 assay was in the same mutual order as the receptor binding activity in the radioreceptor assay. In the RIA, all dose-response curves were parallel except for those obtained with 20 K hGH and with the dimeric form (20 K-20 K)hGH. In this assay, dimeric variants of the constituents 22 K hGH and 24 K hGH were approximately twice as active as 22 K hGH on a molar basis, suggesting about the same affinity between the antibodies and each of the monomeric forms. Determination of the amino acid compositions of the dimeric forms provided support for their content of monomeric constituents as established earlier by electrophoretic analysis.
Effect of amiodarone on non-deiodinative pathway of thyroid hormone metabolism
Authors: Kannan Ram , Chopra Inder J. , Ookhtens Murad , Singh Bramah N. 
Published: December 2008

Abstract
Amiodarone, an iodine containing anti-arrhythmic drug, causes a significant decrease in molar ratio of daily production rates of T3 and T4 from 0.75 in controls to 0.36 in amiodarone-treated rabbits. A model was constructed from the above data which showed that metabolism of T4 via non-deiodinative pathways (e.g. tetraiodothyroacetic acid and/or conjugates) increased from 29% in untreated controls to 66% in amiodarone-treated rabbits. In this study, we have examined the metbolic clearance rate of tetraiodothyroacetic acid in rabbits given amiodarone (20 mg·kg−1·day−1 ip for 3 weeks) or saline (controls). Serum amiodarone and desethylamiodarone levels under the above experimental conditions were 0.20±0.067 and 0.17±0.058 mg/l, respectively, which were in the near-therapeutic range observed in humans. Control and amiodarone-treated rabbits were administered [125I]-tetraiodothyroacetic acid (10 μCi/rabbit) iv and blood was collected at 0.5, 1, 2, 4, 6, 10, 32 and 48 h. Serum tetraiodothyroacetic acid radioactivity was determined by trichloroacetic acid precipitation and ethanol extraction and metabolic clearance rates were calculated from the area under the curve of computer fits to tetraiodothyroacetic acid radioactivity data. Amiodarone treatment decreased metabolic clearance rates significantly from 0.107 ± 0.008 in controls to 0.074 ± 0.009 1/day in amiodarone-treated rabbits (p<0.05). However, when expressed per unit body weight (1·day−1·kg−1), the metabolic clearance rates were not significantly different between the controls and amiodarone-treated rabbits. The terminal serum elimination half-life in the two groups were similar (32.0 ± 6.7 h in controls vs 49.2 ± 12.4 h in amiodarone-treated). Our data suggest that a modest decrease in clearance rate and an increased production rate could result in an increase in serum tetraiodothyroacetic acid levels which may contribute to the reduction in 5'-monodeiodination of iodothyronines documented previously in amiodarone-treated animals. The marginal decrease in metabolic clearance rate of tetraiodothyroacetic acid found in this study suggests that the two-fold increase in the conversion of T4 metabolism to non-deiodinated metabolites/conjugates in amiodarone-treated rabbits results predominantly from an increase in production rate of tetraiodothyroacetic acid.
Incomplete virilization and subclinical mineralocorticoid excess in a boy with partial 17,20-desmolase/17 α-hydroxylase deficiency
Authors: de Lange W. E. , Doorenbos H. 
Published: December 2008

Abstract
A 17-year-old boy is described with impaired virilization and subclinical mineralocorticoid excess owing to combined 17,20-desmolase/17 α-hydroxylase deficiency. His basal plasma progesterone was 20.9 nmol/l (reference value 0.50-1.88), 17-hydroxyprogesterone 21.3 nmol/l (reference value 3.05-4.84), testosterone 6.85 nmol/l (reference value 14.1-22.0), and his excretion of tetrahydro-11-deoxycorticosterone 11.8 μmol/24 h (reference value 1.0-1.5). The differential effects of this combined enzyme deficiency on adrenal and testicular function were studied by ACTH stimulation, dexamethasone suppression, hCG stimulation, and suppression treatment with testosterone.
Isolated human growth hormone deficiency due to the hGH-I gene deletion with (type IA) and without (the Israeli-type) hGH antibody formation during hGH therapy
Authors: Nishi Yoshikazu , Masuda Hiroyuki , Nishimura Shinichiro , Kihara Mikio , Suwa Seizo , Tachibana Katsuhiko , Takeda Michiko , Okada Yoshiaki , Matsuda Ichiro 
Published: December 2008

Abstract
Three Japanese patients with isolated growth hormone deficiency from two different families were shown to be homozygous for deletion of the structural gene for human growth hormone (hGH-I gene). These three patients had the same restriction fragment length polymorphism haplotypes. In patient No. 1, the growth rate initially responded well to pituitary human growth hormone, but growth rapidly ceased concomitantly with the development of high levels of anti-hGH antibodies. He again responded well to recombinant methionyl hGH and recombinant hGH without the methionine residue, even though having high hGH antibodies. Two siblings (Patients No. 2 and 3) showed a rather good response to pituitary hGH treatment without hGH antibodies ever being detected (the Israeli-type). hGH-I gene deletions may not necessarily result in hGH antibody formation. Heterogeneity has been observed in isolated hGH deficiency due to hGH-I gene deletion. hGH-I gene analysis should not be limited to patients with hGH antibody formation and subnormal growth responses to hGH therapy.