bluuebunny/crossref_metadata_2025_split huggingface dataset:
Action and formation of inositol bisphosphate and inositol trisphosphate in rat anterior pituitary cells
Authors: Przylipiak Andrzej F. , Kiesel Ludwig , Karenberg Thomas A. , Przylipiak Maria S. , Runnebaum Benno 
Published: June 2009

Abstract.
Inositol 4,5-bisphosphate and inositol 1,4,5-trisphosphate, administered exogenously at a concentration of 3× 10−5 mol/l increased LH release in superfused rat pituitary cells by 950±267% and 281±83%, respectively. This stimulatory effect was reversible and dose-dependent. Other inositol phosphates (inositol 1-monophosphate, inositol 1,4,5,6-tetrakisphosphate, inositol 1,3,4,5,6-pentakisphosphate and inositol 1,2,3,4,5,6-hexakisphosphate), tested in vitro, did not significantly influence LH release. In saponin-permeabilized cells, the rate of basal and stimulated LH release was twice that in non-permeabilized cells. Penetration of inositol bisphosphate and inositol trisphosphate into saponin-treated pituitary cells did not increase the secretory potency of these agents compared with their effect on non-permeabilized cells. The new findings document that inositol trisphosphate formation occurs within 5-45 s after GnRH (10−7 mol/l) administration and seems to be involved in mediating the rapid, first phase of LH release, whereas inositol bisphosphate formation occurs after 3-15 min and is probably related to later phases of LH secretion. Our results suggest that inositol bisphosphate and inositol trisphosphate are important regulators of the release of luteinizing hormone and can exert their effects not only intracellularly, but also extracellularly.
Relationship between molecular structures of sugars and their ability to stimulate the release of glucagon-like peptide-1 from canine ileal loops.
Authors: Shima Kenji , Suda Takeo , Nishimoto Kayo , Yoshimoto Sachiko 
Published: June 2009

Abstract.
The structure-activity relationship of sugars inducing secretion of glucagon-like peptide-1 from the gut was examined using intestinal loops prepared from the terminal portion of the ileum of dogs. The plasma glucagon-like peptide-1 concentration in a mesenteric vein draining only the looped region of the intestine was increased after infusion of 139 mmol/l solutions of D-glucose, D-galactose, D-glucuronic acid, 3-0-methyl-D-glucose, maltose, sucrose or maltitol into the intestinal lumen, but not after infusion of solutions of D-fructose, D-fucose, D-mannose, D-xylose or lactose. The increases in plasma glucagon-like peptide-1 concentration correlated with the corresponding increases in glucagon-like immunoreactivity induced by these sugars. The plasma glucose level of the regional mesenteric vein increased significantly from the basal level after instillation of D-glucose, but not after instillation of other sugars. It is suggested that cells of the gut have a glucose sensor for release of products of the glucagon gene and that this sensor has specific steric requirements. The sugars that induced glucagon-like peptide-1 release share the molecular features of electron density near C(6), an equatorial hydroxyl at C(2), and an axial hydroxyl at C(1), which could account for their recognition by the glucose sensor to initiate the releases of glucagon-like peptide-1 and glucagon-like immunoreactivity.
Interleukin 1β and tumour necrosis factor α stimulate the release of gonadotropin-releasing hormone and interleukin 6 by primary cultured rat hypothalamic cells
Authors: Yamaguchi Masaaki , Yoshimoto Yasuhiro , Komura Hiroko , Koike Koji , Matsuzaki Noboru , Hirota Kenji , Miyake Akira , Tanizawa Osamu 
Published: June 2009

Abstract.
The abilities of recombinant human interleukin 1β and tumour necrosis factor α to induce release of GnRH and interleukin 6 from primary culture of rat hypothalamic cells were examined. The effect of estradiol on the release of interleukin 6 by these cells was also tested. Both interleukin 1β and tumour necrosis factor α caused significant stimulation of GnRH secretion from the hypothalamic cells within 5 min. The hypothalamic cells secreted interleukin 6 spontaneously, and their secretion over 24 h was stimulated dose-dependently by interleukin 1β, tumour necrosis factor α and estradiol. These results suggest that interleukin 1β and tumour necrosis factor α stimulate the secretions of GnRH and interleukin 6 in the hypothalamus, and that these cytokines may be involved in the mechanism of GnRH secretion in the hypothalamus.
Thelarche variant: A new syndrome of precocious sexual maturation?
Authors: Stanhope Richard , Brook Charles C. D. 
Published: June 2009

Abstract.
We describe 10 girls (mean age 3.7 years, range 1.9-6.9) with precocious sexual maturation and clinical findings intermediate between those of premature thelarche and central precocious puberty. Studies of spontaneous gonadotropin secretion and ovarian ultrasound morphology also revealed findings intermediate between those of isolated premature thelarche and central precocious puberty. There was no response in 6 of the girls treated with GnRH analogue, whether administered intranasally, sc, or by monthly depot injections. We have called this condition thelarche variant because the gonadotropin independence and cyclical nature of breast development may well be due to a lesion of folliculogenesis.
Immunoreactive insulin-like growth factor II in urine
Authors: Zumkeller Walter , Hall Kerstin 
Published: June 2009

Abstract.
Insulin-like growth factor II and insulin-like growth factor binding protein-1 were identified and quantified in the urine of 23 healthy subjects between 17 and 76 years of age. IGF-II was measured after separation by gel chromatography at low pH and compared with IGF-I levels in the same samples, whereas IGF binding protein-1 was measured in dialysed urine. Urinary IGF-II was found at much higher concentrations than IGF-I (mean ±sem: 717±69 vs 110±5 ng/mmol creatinine). The chromatographic profile indicates that pro-IGF-II may also be present. The concentrations of IGF-II appear to be less variable than the other reported parameters. The mean IGF binding protein-1 concentrations in these urine samples was 414±83 ng/mmol creatinine. IGFs in the urine are in part bound to binding proteins.
Inhibition by immunoglobulin G of synthesis of thyroid hormone in thyroid cultures from hypothyroid patients with goitrous Hashimoto's thyroiditis
Authors: Noh Jaeduk , Hamada Noboru , Saito Hifumi , Yoshimoto Midori , Iwasaki Hiroyuki , Ozaki Osamu , Okamoto Yasuyuki , Ito Kunihiko , Morii Hirotoshi 
Published: June 2009

Abstract.
Recently, thyroid microsomal antigen was identified as thyroid peroxidase, and thyroid microsomal antibody was found to inhibit thyroid peroxidase activity in vitro. We investigated the possibility that anti-microsomal antibody inhibits the iodination of tyrosine, in vivo. Immunoglobulin G with or without anti-microsomal antibody from hypothyroid patients with goitrous Hashimoto's thyroiditis inhibited thyroid hormone synthesis in cultured slices of normal human thyroid tissue. IgGs with anti-microsomal antibody inhibited 125I thyroidal uptake and thyroid hormone synthesis stimulated by TSH more than normal IgG did. However, the same results were obtained with IgGs without anti-microsomal antibody. This effect did not involve anti-microsomal antibody, anti-thyroglobulin antibody, TSH-binding inhibitor immunoglobulin, thyroid stimulation-blocking immunoglobulin, or the cAMP level of the thyroid tissue. The ratio of organic I to inorganic I with stimulation by TSH in slices incubated with IgG from hypothyroid patients with goitrous Hashimoto's thyroiditis or normal IgG was not significantly different, but was significantly higher in slices incubated with methylmercaptoimidazole. Therefore, IgG from hypothyroid patients with goitrous Hashimoto's thyroiditis mainly suppressed 125I thyroidal uptake, rather than inhibiting thyroid peroxidase activity. In addition, this IgG was present in the serum of 11 of the 12 hypothyroid patients with Hashimoto's thyroiditis studied. This IgG may be involved in the mechanism that causes hypothyroidism in some patients with goitrous Hashimoto's disease.
The blunting of the thyrotropin response to repeated thyrotropin-releasing hormone administration is reduced by dopaminergic blockade both at normal and elevated serum levels of thyroid hormones
Authors: Erfurth Eva Marie T. , Attewell Robyn , Hedner L. Pavo 
Published: June 2009

Abstract.
Fifteen premenopausal women were investigated in the follicular phase of the menstrual cycle with two TRH tests within an interval of 48 to 96 h. Ninety min before each TRH test either 10 mg metoclopramide or saline was injected iv in randomized order. The same procedure was repeated in the following menstrual cycle after pretreatment with T4 (0.5 mg daily for 6-14 days). At least 2 months later the same procedure was repeated with T3 pretreatment (60-120 μg for 6-8 days) in 9 of them. A multiple regression analysis was used in modelling the relationships between TSH release and serum free T3, T4 and estradiol levels, adjusting for the presence of metoclopramide and the order of the test. No correlation was found between the TSH response to TRH and the serum estradiol level. The TSH response to the second TRH test was approximately half the first one, both in the control situation and after treatment with T4 or T3. The blunting of the TSH response to the second TRH administration was significantly reduced by metoclopramide, both at normal and elevated thyroid hormone levels, suggesting that a dopaminergic mechanism takes part in the blunting.
The effect of pre-operative potassium iodide therapy on antibody production
Authors: Wilson R. , Mc Killop J. H. , Thomson J. A. 
Published: June 2009

Abstract.
Previous studies have suggested that iodide may increase the incidence of thyroid disease and antithyroid antibodies in predisposed individuals. This study has considered the effects of pre-operative potassium iodide (60 mg twice daily, for 10 days) on the immune system of patients with Graves' disease. The treatment regimen used maintained all patients in a clinically and biochemically euthyroid state prior to surgery. Potassium iodide significantly increased serum thyrotropin receptor antibody levels and B cell activity as determined by increased immunoglobulin production from mitogen stimulated peripheral blood lymphocytes. These effects were not observed in the two control groups of Graves' disease patients. Our in vivo findings would support previous in vitro work showing that potassium iodide does act on the immune system and this may be the mechanism by which iodide induces thyroid dysfunction in predisposed individuals.
Improved sensitivity of serum thyrotropin measurements. Studies on serum sex hormone-binding globulin in patients with reduced serum thyrotropin
Authors: Faber Jens , Gam Arne , Siersbæk-Nielsen Kaj 
Published: June 2009

Abstract.
Most serum TSH assays have a working sensitivity (i.e. the lowest TSH value with an inter-assay co-efficient of variation below 10%) around 0.15-0.4 mU/l, which also is the critical area for cut off for further thyroid profile testing when serum TSH is used as a "first line test". A new assay (BeriLux hTSH) based on chemiluminescence was evaluated, and demonstrated a theoretical sensitivity (mean + 2 sd of the zero standard) of 0.005 mU/l and a working sensitivity as low as 0.04 mU/l. Reference range was 0.18-2.60 mU/l (N=33). Sixty-eight percent (13/19) of hyperthyroid patients had serum TSH <0.005 mU/l, all had serum TSH <0.037 mU/l. We studied two groups of patients with normal free T4 and T3 indices but serum TSH <0.15 mU/l as measured by an immunoradiometric assay. Thirty-five percent (7/20) of patients with nontoxic goitre and 5% (1/20) of L-T4 treated patients had serum TSH <0.005 mU/l; and in 60% (11/20) and 30% (6/20), respectively, the levels overlapped the total range for hyperthyroidism. Serum levels of sex hormone-binding globulin expressed as percent of the reference median for the relevant sex (SHBG%) were elevated in both groups of patients (p<0.01). Approximately 50% of those with serum TSH overlapping the hyperthyroid range had serum SHBG% levels above reference range. In conclusion, this assay seems superior to most previously reported assays concerning working sensitivity, but it still leaves us with a group of clinically euthyroid patients who has unmeasurably low serum TSH. Many of these patients have increased serum SHBG%, and might in fact be subclinically hyperthyroid.
Characterization of melatonin receptors in the ram pars tuberalis: influence of light
Authors: Pelletier Jean , Castro Bertrand , Roblot Georges , Wylde Renée , de Reviers Marie-Madeleine 
Published: June 2009

Abstract.
The present study was conducted to assess the binding of [125I]melatonin to frozen unfixed sections of pars tuberalis/median eminence tissue from Ile-de-France rams exposed or not exposed to light before slaughter. The specificity of [125I]melatonin binding to the pars tuberalis tissue was revealed by autoradiography and the magnitude of binding as related to the pars tuberalis area was determined after incubation and counting of pars tuberalis/median eminence sections. Subsequent studies with sections incubated with [125I]melatonin indicated that 1. the binding sites were saturable; 2. binding was stable for 24 h at 20°C, but unstable at 28 or 37°C; 3. melatonin and [12 7I]melatonin had a similar potency to compete with [125I]melatonin for binding sites, whereas other ligands such as serotonin or N-acetylserotonin were devoid of activity, and 4. by Scatchard analysis, the constant affinity Ka was found to be high in the 1010 l/mol range. Rams exposed to light throughout the night prior to slaughter presented a significant increase in the apparent number of [125I]melatonin binding sites in comparison to animals maintained under darkness (2.25±0.30 vs 1.01±0.17 fmol/mm2 pars tuberalis, p<0.01), whereas Ka values were similar in both groups. These results indicate the presence of true melatonin receptors in the pars tuberalis of the ram. Furthermore, they suggest that their apparent number is light-dependent.
Characterization of the acidic forms of ovine pituitary luteinizing hormone
Authors: Keel B. A. , Harms R. L. , Grotjan H. E. 
Published: June 2009

Abstract.
The naturally occurring acidic forms of ovine pituitary LH were examined by chromatofocusing. Immunoreactive oLH eluted as six variants (elutions pHs of >7.4, 6.83, 6.59, 6.23, 5.5-4.0, and <4.0, designated as "basic forms" and variants II-VI, respectively). In rams, the percentage in each variant averaged 46, 9, 28, 10, 5 and 2, respectively, of the total LH recovered. oLH from non-implanted wethers or wethers implanted with dihydrotestosterone, E2 or dihydrotestosterone +E2 eluted as six similar variants but differences were noted in the distribution of oLH among the variants. Compared to rams, pituitary extracts from non-implanted and dihydrotestosterone-implanted wethers contained significantly higher percentages of oLH eluting as basic forms. In contrast, E2- or dihydrotestosterone-implanted wethers exhibited significantly higher percentages of oLH in the acidic variants. Each of these variants was demonstrated to contain biologically active oLH using an in vitro bioassay. Furthermore, the basic forms of oLH were the most abundant biologically active forms present in pituitary extracts. These results suggest that in addition to the seven basic forms of oLH previously described, there are at least five naturally occurring acidic forms of oLH in pituitary extracts which are biologically active, and the distribution of pituitary oLH among its isohormones, including the acidic forms, appears to be modified by steroids.
Effect of 2-buten-4-olide, an endogenous suppressant of feeding, on reproductive function in rats
Authors: Shitsukawa Keiji , Irahara Minoru , Kanematsu Toyokazu , Azuma Keijiro , Aono Toshihiro 
Published: June 2009

Abstract.
The effects of 2-buten-4-olide, an endogenous feeding suppressant, on the estrous cycle and LH secretion were studied to determine the influence of this compound on reproductive function. Estrous cycling female Wistar rats were treated ip with 2-buten-4-olide (0, 30 or 100 mg·kg−1·day−1) for 2 weeks. Treatment with 100 mg·kg−1·day−1delayed the estrous cycle. 2-Buten-4-olide increased the pituitary content of LH (1651.3±164.4 vs 927.7±65.1 ng/pituitary; p<0.01), and decreased the serum LH level compared with the control level in diestrus (0.16±0.01 vs 0.26±0.03 μg/l; p<0.05). However, it did not affect the GnRH content of the mediobasal hypothalamus. The direct effects of 2-buten-4-olide on the pituitary response to GnRH was examined by perifusing the pituitary. Medium containing 2-buten-4-olide (10−4 mol/l) suppressed the pituitary response to GnRH (2 μg/l) (percent increase at 50 min after start of GnRH stimulation: 180±47 vs 406±66%; p<0.05). These findings suggest that 2-buten-4-olide is involved in the regulation of pituitary gonadotropin secretion directly by suppressing the pituitary responsiveness to GnRH, and that 2-buten-4-olide may play an important role in starvation-induced anestrus.
Iodine deficiency diseases in Switzerland one hundred years after Theodor Kocher's survey: A historical review with some new goitre prevalence data
Authors: Bürgi Hans , Supersaxo Zeno , Selz Beat 
Published: June 2009

Abstract.
In certain regions of Switzerland, before prophylaxis, 0.5% of the inhabitants were cretins, almost 100% of schoolchildren had large goitres and up to 30% of young men were unfit for military service owing to a large goitre. Iodization of salt was introduced in 1922 at 3.75 mg I per kg and the iodine content was doubled twice, in 1962 and 1980, to the present 15 mg I per kg. In 1988, 92% of retail salt and 76% of all salt for human consumption (including food industry) was iodized, even though its use is voluntary. Urinary iodine excretion, previously between 18 and 64 μg per per day, has now risen to 150 μg per day. No new endemic cretins born after 1930 have been identified. Goitre disappeared rapidly in newborns and schoolchildren, more slowly in army recruits, and incompletely in elderly adults. In some Cantons (by constitution in charge of health matters and the salt monopoly) which allowed iodized salt only in 1952, disappearance of goitre lagged behind accordingly, proof that iodized salt was the cause of regression. The Swiss data provide evidence that isolated deafness, mental deficiency, and short stature, each without the other attributes of cretinism have also decreased. Adverse effects of iodized salt were minimal, possibly because the initial iodine content of salt was chosen very low. Iodization of salt has proved a highly cost-effective preventive measure in Switzerland.
Effects of galanin and calcitonin gene-related peptide on insulin and glucagon secretion in man
Authors: Ahrén Bo 
Published: June 2009

Abstract.
To study the influence of the pancreatic neuropeptides, galanin and calcitonin gene-related peptide, on insulin and glucagon secretion in man, synthetic porcine galanin (80 pmol·kg−1·min−1; N=6) or synthetic human calcitonin gen-related peptide (10 pmol·kg−1·min−1; N = 5) was infused intravenously in human volunteers. Following 5 min of infusion, arginine (5 g bolus + 10 mg·kg−1·min−1) was given. Galanin did not affect basal or arginine-stimulated insulin secretion judged from determinations of plasma insulin and C-peptide. Similarly, galanin did not affect arginine-stimulated glucagon secretion. Calcitonin gene-related peptide did not affect basal or arginine-stimulated insulin or glucagon secretion. However, calcitonin gene-related peptide slightly potentiated the arginine-induced hyperglycemia (p<0.01). Thus, in man, galanin has no influence on insulin or glucagon secretion when infused at 80 pmol·kg−1·min−1, whereas CGRP at 10 pmol·kg−1·min−1 induces slight hyperglycemia.
Ovarian response patterns to human menopausal gonadotropin in mixed hyperandrogenemia
Authors: Hamori Miklos , Török Attila , Zwirner Manfred , Tinneberg Hans-Rudolf 
Published: June 2009

Abstract.
Twenty-eight hyperandrogenemic women suffering from infertility owing to chronic anovulation were treated with hMG. Only 7 patients exhibited the typical polycystic ovarian appearance of multiple subcortical cysts, however, a wide range (6-15 cm3) of ovarian volume was observed. The LH/FSH ratio was consistently lower than 2.5 and circulating androgens of both ovarian and adrenal origin were elevated. The 4 days dexamethasone suppression test showed more than 80% suppression of dehydroepiandrosterone-sulphate and a variable (40-60%) reduction of testosterone and androstenedione levels. Two different patterns of follicular development were observed in response to hMG. Sixteen patients exhibited polycystic ovarian reaction, whereas 12 women had a follicular growth pattern similar to that seen in hMG-stimulated normo-ovulatory subjects. Patients with polycystic ovarian reaction showed a significantly increased androstenedione response to hMG when compared with the other group. Moreover, the non-stimulated ovarian volume was found to be markedly greater than in subjects without polycystic reaction. Thus, ovarian stimulation of patients with mixed hyperandrogenemia may elucidate the presence of borderline polycystic ovaries; furthermore the increased accumulation of androstenedione may suggest an inherent ovarian failure.
On the usefulness of levothyroxine suppressive therapy in the medical treatment of benign solitary, solid or predominantly solid, thyroid nodules
Authors: Celani Marco F. , Mariani Maurizio , Mariani Giuliano 
Published: June 2009

Abstract.
The efficacy of levothyroxine suppressive therapy in the treatment of benign solitary thyroid nodules is controversial. In order to investigate this issue further we studied 122 patients with a solitary, solid or predominantly solid, thyroid nodule. The benign (colloid) nature of all nodules was proved by fine-needle aspiration biopsy. At the pertechnetate-99m thyroid scanning 91% of the nodules were "cold" and 9% "warm". All the patients received suppressive oral doses of levothyroxine (0.1 to 0.2 mg/day). Fifty-three patients were treated with levothyroxine for 6 months, 31 for 9 months and 38 for 12 months. The size of each nodule before and after treatment was evaluated by high-resolution ultrasonography. The actual suppression of TSH secretion was monitored at 3-month intervals using an ultrasensitive immunometric assay. At the end of levothyroxine treatment, patients were classified as responders (decrease in nodule volume ≥50%, 68/122 = 55.7%; mean percent change in nodule volume = −77.1 ± 15.7%), partially responders (decrease in nodule volume <50%, 24/122 = 19.7%; mean percent change in nodule volume = −27.5±10.1%), and nonresponders, when either no change in nodule volume (16/122 = 13.1%) or an increase in nodule volume (14/122 = 11.5%) was observed. In each group serum free T4 rose significantly in response to levothyroxine therapy, whereas serum free T3 remained unchanged. TSH levels were undetectable in all patients. Both the proportion of responders, partially responders and nonresponders, and the mean percent decrease in nodule volume in the responder group were not significantly different in patients treated with levothyroxine for 6, 9 or 12 months, respectively. Therefore, it appears that levothyroxine therapy is effective within 6 months in reducing the size of colloid solitary, solid or predominantly solid, thyroid nodules or in preventing their further growth in about 90% of our patients.