bluuebunny/crossref_metadata_2025_split huggingface dataset:
IMPAIRED CYCLIC-AMP RESPONSE TO THYROTROPHIN IN CONGENITAL HYPOTHYROIDISM WITH THYROGLOBULIN DEFICIENCY
Authors: Medeiros-Neto Geraldo A. , Knobel Meyer , Bronstein Marcello D. , Simonetti José , Filho Fadlo Fraige , Mattar Emilio 
Published: December 2008

ABSTRACT
A 19 year old man had congenital hypothyroidism and severely retarded development. His thyroid gland was not enlarged and laboratory findings included low serum concentration of T4 (2.8 μg/100 ml) and T3 (16 ng/100 ml) with a high level of TSH (52 μU/ml) that rose to 192 μU/ml after TRH. 131I uptake by the thyroid was normal (41.5 % at 24 h) and did not show a normal increase after exogenous TSH administration (49.5 % at 24 h). The perchlorate discharge test was negative and no antibodies against thyroid antigens were found. Studies on the biopsy specimen revealed low iodide trapping by the thyroid slices and no formation of cyclic AMP after TSH was added to the medium. The endogenous TSH of the patient was biologically active increasing cyclic adenosine monophosphate c-AMP concentration in normal thyroid slices. No thyroglobulin was found in the thyroid tissue either by immunological or ultracentrifugational methods. An increased proportion of iodoalbumin was present in the serum. We postulate that the fundamental defect in this gland is an impaired generation of c-AMP by the defective thyroid cell and deficiency of thyroglobulin formation resulting in inadequate thyroxine and triiodothyronine synthesis.
ADENYL CYCLASE ACTIVITY IN HUMAN THYROID PLASMA MEMBRANES FROM NORMAL HUMAN THYROID TISSUE AND THYROID ADENOMAS
Authors: Wålinder O. , Karlsson F. A. , Dahlberg P. A. 
Published: December 2008

ABSTRACT
The adenylcyclase (AC) activity of crude human thyroid plasma membranes were studied in some detail and conditions for optimal cyclic AMP-production established. Membranes from eight "cold" and two "hot" thyroid adenomas were investigated and compared to membranes from corresponding normal, paranodular tissues. The investigated membranes were found to contain similar basal AC activities, which were stimulated three to five times with TSH and 20–30 times with fluoride. Further, no difference in the TSH-sensitivity of AC from normal and "cold" adenomas could be detected. Thyrotrophin 0.02 mU/ml caused a measurable and 0.15 mU/ml a half-maximal stimulation of the cAMP-production. The data indicate, that disturbances of thyroid hormone production characteristic of thyroid adenomas, are not caused by alterations of the TSH-AC system and suggest that in a thyroid cell the degree of thyroid hormone synthesis do not alter the amount of plasma membrane-bound adenylcyclase.
LOW MOLECULAR WEIGHT INTRACELLULAR IODOCOMPOUNDS WITH LONG INTRATHYROIDAL HALF-LIFE: REMNANTS OF THYROGLOBULIN HYDROLYSIS?
Authors: Haeberli A. , Engler H. , von Grünigen C. , Kohler H. , Studer H. 
Published: December 2008

ABSTRACT
in this paper additional information on low molecular weight, soluble, intrathyroidal iodocompounds with slow metabolic rate is provided. These compounds have previously been localized autoradiographically within the follicular cells.
Radioiodide was administered to rats on a normal iodine intake (6–7 μg/day) for 80 days to approach isotopic equilibration of the intrathyroidal iodine with the dietary radioiodide. When the isotope was omitted from the diet the intrathyroidal radioiodine was released with an apparent half-life of approximately 12 days. When the individual soluble components carrying radioiodine were analyzed after separation on Sephadex G-200, different apparent half-lives were found, the half-life of thyroglobulin (Tgb) being roughly 10 days and that of the low molecular weight iodocomounds being in the order of 60 to 100 days or more. In addition to the soluble low molecular weight iodocompounds, the radioactivity in the particulate fraction increased by 100 % during the tracer washout when compared to Tgb and the total soluble fraction.
The soluble slow turnover iodocompounds contained a higher percentage of carbohydrate and total iodine than Tgb, while the relative amounts of each sugar analyzed (hexoses, fucose, hexosamine and sialic acid) were close to those in Tgb. Sephadex G-25 chromatography of the low molecular weight iodocompounds obtained after Sephadex G-200 separation resulted in the separation of 4 peaks. Two peaks identified as iodopeptides could be further analyzed. The carbohydrate composition of these peptides was similar to that of 2 glycopeptides obtained after in vitro enzymatic hydrolysis of purified Tgb with pronase.
Slow equilibration with radioiodine, long apparent intrathyroidal half-life and carbohydrate content similar to that of Tgb, taken together with previously published data on intracellular localization of soluble intrathyroidal iodocompounds, suggest that the low molecular weight iodocompounds are products of in vivo hydrolysis of engulfed Tgb droplets.
URINARY EXCRETION OF CALCIUM, HYDROXYPROLINE AND 3′,5′-CYCLIC ADENOSINE MONOPHOSPHATE IN PRIMARY HYPERPARATHYROIDISM
Authors: Halse Johan , Gordeladze Jan O. 
Published: December 2008

ABSTRACT
Urinary excretion of calcium (Ca), hydroxyproline (Hyp) and 3′,5′-cyclic adenosine monophosphate (cAMP) was measured during fasting, and in the afternoon, over a 3 day period. Twelve hyperparathyroid patients, of whom 6 were re-studied after successful parathyroid surgery, and 10 control subjects participated, and were maintained on a collagen free diet for the duration of the study.
Expressed as creatinine ratio values, Hyp was significantly higher in the morning than during the afternoon, whereas the Ca excretion pattern showed low morning and high afternoon values for all groups. cAMP excretion did not change during the two sampling periods.
Large day to day variations for each parameter were observed in the individual patient. The value of cAMP measurements in the diagnosis of primary hyperparathyroidism was confirmed. The results may imply that a diurnal variation in Hyp excretion exists in primary hyperparathyroidism and that food intake produces a suppression of Hyp excretion, possibly secondary to suppression of parathyroid function or, in our view, to increased calcitonin excretion.
EFFECT OF CYPROHEPTADINE ON THYROTROPHIN AND PROLACTIN SECRETION IN NORMAL MAN
Authors: Golstein J. , Vanhaelst L. , Bruno O. D. , L'Hermite M. 
Published: December 2008

ABSTRACT
In order to investigate the effect of cyproheptadine, a compound with antiserotoninergic activity, on the secretion of thyrotrophin (TSH) and prolactin (PRL), the nocturnal secretory patterns of these hormones have been studied in 4 normal men in the basal state and after an oral treatment with the drug. In addition, the TSH and PRL responses to TRH of 6 women were compared in the basal conditions and after cyproheptadine treatment.
The TSH nocturnal secretion was slightly modified by drug treatment. The response to TRH as well as the basal levels were comparable in the treated and non-treated subjects. In contrast, the PRL secretion measured through the nocturnal investigation was significantly inhibited by cyproheptadine administration as were the PRL basal levels in the TRH test. The PRL response to TRH was comparable in both situations.
EFFECT OF GROWTH HORMONE AND PEPTIDE FRACTIONS CONTAINING SOMATOMEDIN ACTIVITY ON GROWTH AND CARTILAGE METABOLISM OF SNELL DWARFMICE
Authors: van Buul-Offers Sylvia , Van den Brande Jan Leo , Hoogerbrugge C. M. , Dumoleijn L. , v.d. Klundert P. L. M. 
Published: December 2008

ABSTRACT
In order to obtain more information about a possible role of somatomedin (SM) in vivo, increase in length and weight, costal cartilage activity (35SO4 = and 3H-methyl-thymidine incorporation), organ weight and serum glucose levels were studied in Snell dwarfmice, during treatment with human growth hormone (hGH), l-thyroxine (T4), insulin and a semipurified SM-preparation (SM-P1).
SM-P1, hGH and T4 caused a significant increase in length and weight, whereas insulin was not effective in a dosage similar to the insulinlikeactivity of the SM-P1 preparation measured by radioreceptorassay. The effect obtained with the SM-preparation cannot be due to contamination of GH, prolactin, T4, insulin or testosterone.
Costal cartilage activity was measured three days after initiation of treatment by incubation immediately after sacrifice in plasma free medium. Both sulphate and thymidine incorporation were increased by the administration of SM-Pl and hGH, compared to buffer treated controls. After treatment for four weeks no differences between treated and untreated animals in cartilage activity could be observed anymore.
Both SM-P1 and hGH induced weight gain in most organs. An outspoken effect was seen on lymphoid organs, the submandibular salivary glands and muscle, a sizable effect was present on the kidneys and a small effect, not reaching significance for the SM-Pl treated group on brain weight.
An impression of divergence was seen with liver weight, which increased on hGH while there was a small and not significant rise on SM-P1. A definite discrepancy was found in skinfold thickness, which was essentially unchanged on hGH and increased on SM-P1. Testes and epididymal fat, though probably increasing their weights, were in insufficient number to do statistics on.
Serum T4 is low in untreated dwarfmice. It is increased to a subnormal level after hGH administration whereas no effect is observed with SM-P1. The dose dependent effect of insulin, measured by radioimmunoassay, on the induction of hypoglycaemia is markedly similar to the effect of nonradioimmunoactive insulin-like activity of SM-P1 as measured by radioreceptorassay. The hypoglycaemia induced with insulin and the SM-preparation is reduced by adding 10 % glucose to the diet.
In conclusion: SM-P1 shows growth stimulating and insulin-like actions in vivo. The pattern of effects obtained with hGH, T4 and insulin differs from that of SM-P1.
KLINEFELTER'S SYNDROME: EFFECTS OF OESTROGEN ON GROWTH HORMONE, PROLACTIN AND THYROTROPHIN RELEASE, AND ON THYROTROPHIN AND PROLACTIN RESPONSES TO THYROTROPHIN-RELEASING HORMONE
Authors: Barbarino Antonino , De Marinis Laura 
Published: December 2008

ABSTRACT
In 4 normal men and 8 patients with Klinefelter's syndrome the effects of oestradiol-17 β (15μg/kg daily for 8–13 days) on serum levels of pituitary hormones were investigated. Control levels of gonadotrophins in the Klinefelter patients were significantly higher than in the normal males, whereas serum testosterone (T) levels were lower. Oestradiol induced a decrease in serum gonadotrophin concentrations in both the control subjects and the Klinefelter patients, whereas a testosterone suppression was observed in the normal subjects, but not in the Klinefelter patients. Control serum growth hormone (hGH), and prolactin (hPRL) levels were of comparable magnitude in both groups and significantly increased during oestradiol administration. Serum thyrotrophin (TSH) levels were normal before and during oestrogen treatment. Basal serum oestradiol levels were within the normal male range, and were increased during treatment. Prolactin and thyrotrophin responsiveness to TRH stimulation was examined in Klinefelter patients before and during oestrogen administration. Before treatment, hPRL responses to TRH were higher than those observed in normal men. During oestrogen treatment hPRL responses to TRH were significantly increased when compared to those observed before treatment. TSH responses to TRH were normal both before and during treatment.
These studies indicate that in patients with Klinefelter's syndrome pharmacological doses of oestrogen induce different effects on the hypothalamic-pituitary axis, as regards the release of gonadotrophins, prolactin, thyrotrophin, and growth hormone, similar to those observed in normal men. This fact supports the conclusion that in Klinefelter's syndrome the abnormality in the pituitary-gonadal feedback mechanism is selectively confined to the testosterone feedback control of gonadotrophin secretion. Finally, in patients with Klinefelter's syndrome, oestrogen is capable of inducing a significant increase of the hPRL response to TRH stimulation.
FURTHER STUDIES ON HYPOTHALAMIC-PITUITARY-TESTICULAR FUNCTION IN OLD RATS
Authors: Pirke Karl M. , Krings Beate , Vogt Hermann-J. 
Published: December 2008

ABSTRACT
The dysfunction of the hypothalamic-pituitary-gonadal axis in old age was studied in 24-month old male Wistar rats which were compared with 3-month old animals. The hypothalamic LH-RH content and the pituitary LH were significantly lower in the old than in the young adult animals. The plasma concentrations of LH and testosterone were significantly higher in the young rats. The primary cause of these age-dependent changes probably is a hypothalamic dysfunction. When isolated Leydig cells of young and old rats were incubated in vitro, the testosterone secretion per cell was significantly smaller in old than in young cells with as well as without HCG stimulation.
In vivo stimulation of rats by iv injection of biologically active iodinated hCG revealed that the intratesticular uptake of the gonadotrophin was not different in young and old rats. The testosterone response, however, was significantly reduced in old age. An in vitro "desensitisation" experiment in which the LH receptor capacity was artificially reduced demonstrated that the 40 % reduction of receptor capacity in old testes as described earlier will not impair the testicular uptake of gonadotrophin from blood. Repeated injection of hCG results in equally elevated testosterone concentrations in young and old rats.
PERSISTING SUPPRESSION OF PROLACTIN SECRETION AFTER LONG-TERM TREATMENT WITH BROMOCRIPTINE IN PATIENTS WITH PROLACTINOMAS
Authors: Eversmann T. , Fahlbusch R. , Rjosk H. K. , von Werder K. 
Published: December 2008

ABSTRACT
The effect of bromocriptine withdrawal after long-term treatment on prolactin levels has been investigated in thirty-seven patients with prolactinomas. In ten patients with macroprolactinomas and post-operatively excessively high prolactin levels persisting suppression of prolactin secretion after bromocriptine withdrawal has been observed. This effect was not observed in patients with microprolactinomas or macroprolactinomas with only moderately elevated prolactin levels. The degree of persisting suppression correlated to the height of prolactin levels before treatment and to the duration of bromocriptine therapy. No correlation was found between the rise of prolactin levels after bromocriptine withdrawal and withdrawal time. It is suggested that the persisting suppression of prolactin levels is a sequence of reduction in tumour size. This anti-proliferative action of bromocriptine seems to be specific for the prolactin secreting cells in macroprolactinomas with high proliferation rate and high prolactin turn-over. These findings offer new possibilities in the management of patients with macroprolactinomas.
EFFECT OF THE NORETHISTERONE MINIPILL ON THE PLASMA LEVELS OF BIOLOGICALLY AND IMMUNOLOGICALLY ACTIVE LUTEINIZING HORMONE IN WOMEN
Authors: Balogh A. , Robertson D. M. , Diczfalusy E. 
Published: December 2008

ABSTRACT
The relationship between biologically and immunologically active luteinizing hormone (LH) in plasma was investigated daily throughout a menstrual cycle in 29 women before and during the second month of the oral administration of norethisterone (Mini-Pe®, Astra-Syntex) in a daily dose of 0.3 mg. The biological activity was determined by an in vitro bioassay and the immunological activity by a radioimmunoassay method. A characteristic midcycle surge of LH was observed with both assay methods in all 29 control cycles. Of the 29 treatment cycles studied with both assay methods, 10 cycles exhibited a similar LH pattern, although the levels of both activities were significantly depressed (P < 0.001) during all phases of the cycle. The biological to immunological (B/I) ratios of plasma LH between the treatment and control cycles were not significantly different.
Of the remaining 19 treatment cycles, in which no "midcycle" LH peak was evidenced, the levels of both activities in the treatment periods were significantly lower (P < 0.05) than in the follicular phase and significantly higher than in the luteal phase (P < 0.05) of the control cycles. The overall B/I ratios were significantly lower in the treatment periods than in the control cycles (P < 0.001). However, the influence of this difference on the general pattern of immunological activity in comparison with that of biological activity was relatively small.
It is concluded that the irregular patterns of immunological hLH activity which are observed after treatment with low doses of norethisterone are similar to those of the biological activity.
THE INFLUENCE OF OESTROGEN ADMINISTRATION IN VIVO ON IN VITRO PROLACTIN RELEASE
Authors: Jaques Sandford , Gala Richard R. 
Published: December 2008

ABSTRACT
The influence of oestrogen administered to the ovariectomized rat on the interaction between dopamine (DA) and thyrotrophin releasing hormone (TRH) on the release of radioimmunoassayable (RIA) and [3H] leucine incorporated into prolactin ([3H]PRL) was examined in vitro. Dopamine had a more marked suppressing effect on newly synthetized PRL (80 %), as determined [3H]PRL, than on total PRL (50 %), as determined by RIA-PRL. The administration of 5 μg of oestradiolbenzoate (OeB) for 7 days resulted in blocking the suppressing effect of DA when RIA-PRL was measured but not when [3H]PRL was measured. The administration of 5 μg of OeB enabled TRH to partially override the suppressing effect of DA and the degree of response was more marked when RIA-PRL was measured than when [3H]PRL was measured. The administration of 50 μg of OeB for 3 days enabled TRH to override the DA blockade of prolactin release to levels comparable to that of the control when RIA-PRL was measured but had little to no effect on [3H]PRL. The results are discussed in relation to the two storage pools of PRL in the pituitary and the data suggest that DA acts predominantly to suppress the newly synthetized, rapidly releasable pool. Oestrogen acts to block DA action on the older more stable PRL pool. The ability of TRH to override the DA blockade of PRL release depends upon the presence of oestrogen; here TRH acts predominantly on the older more stable pool of PRL. Oestrogen's action on disrupting the DA suppression of PRL release appears to be related to the time of day the hormone is administered subsequent to when the pituitary is exposed to DA in vitro.
THE EFFECTS OF TETRAIODOTHYROACETIC AND TRIIODOTHYROACETIC ACIDS ON THYROID FUNCTION IN EUTHYROID AND HYPERTHYROID SUBJECTS
Authors: Burger A. G. , Engler D. , Sakoloff C. , Staeheli V. 
Published: December 2008

ABSTRACT
The effects of tetraiodothyroacetic (Tetrac) and triiodothyroacetic acids (Triac) on thyroid function have been investigated in euthyroid and hyperthyroid subjects. 50, 100, 200, 400 or 800 μg of Triac were administered to 8 euthyroid volunteers three times (tds) over a 24 hour period. 3 × 800 μg Triac/24 h was sufficient to cause a significant reduction in serum T3. Tetrac, given as an iv bolus of 3600 μg, produced a sustained reduction in serum T3 for up to 4 days after the injection. Intermediate doses of Tetrac (1200 μg) or Triac (400 μg tds) significantly reduced the TSH response to TRH (66 % and 43 % respectively).
Seven hyperthyroid patients received Triac 200 μg tds for 2 days, and in 2, a rapid decrease in serum T3 was seen. Similar changes in serum T3 were also produced with iodide administration.
The results suggest that 1) in euthyroidism, Tetrac and Triac act directly at the pituitary level to inhibit the TSH response to TRH; 2) in some cases of hyperthyroidism, Triac produces a block in T3 secretion by virtue of the iodide produced by its metabolism.
FAILURE OF METOCLOPRAMIDE TO INFLUENCE LH, FSH AND TSH SECRETION OR THEIR RESPONSES TO RELEASING HORMONES
Authors: Spitz Irving M. , Trestian Stefan , Cohen Haim , Arnon Naomi , LeRoith Derek 
Published: December 2008

ABSTRACT
Intravenous metoclopramide (MET) (10 mg) induced a brisk PRL response with a mean ± sem peak of 85.3 ± 7.7 ng/ml maximal at 30 min. l-Dopa, but not atropine pre-treatment, attenuated the prolactin (PRL) response to MET. This indicates that the antidopaminergic properties of MET mediate PRL secretion. MET did not influence basal levels of TSH, LH or FSH. Neither did it affect their response to the respective releasing hormones. Our results indicate that dopaminergic blockade induced by iv MET, does not influence the secretion of the pituitary glycoprotein hormones.
THYROTROPHIN-RESPONSIVE ADENYLATE CYCLASE ACTIVITY IN THYROID TOXIC ADENOMA
Authors: Toccafondi Roberto S. , Rotella Carlo M. , Tanini Annalisa , Fani Patrizia , Arcangeli Paolo 
Published: December 2008

ABSTRACT
The adenylate cyclase system was studied in hyperfunctioning autonomous nodules in comparison with normal thyroid tissue. The basal, TSH- and NaF-stimulated adenylate cyclase activities were tested in purified plasma membrane preparations. Basal enzyme activity in membranes from hyperfunctioning nodules was variable and the response to TSH was either normal, low or absent. The present study demonstrates that an intact adenylate cyclase activity, hyporesponsive to TSH, may exist in the cell membrane of the adenoma.
SYMPATHECTOMY AND PROSTAGLANDIN DEFICIENCY DO NOT PREVENT GASTROGENIC HYPERGLYCAEMIA AND HYPERINSULINAEMIA
Authors: Schusdziarra V. , Rouiller D. , Unger R. H. 
Published: December 2008

ABSTRACT
To examine the mechanism of the recently reported effect of an acidified intragastric test meal on insulin release and glucose homeostasis, a liver extract test meal at either pH 2 or pH 7 was instilled into the stomach of normal dogs and dogs with a chemical sympathectomy or indomethacin-induced prostaglandin deficiency, all of which had a bisected pylorus and gastric fistula. In the normal dogs the instillation of the liver meal at pH 2 elicited a significant rise in plasma glucose, glucagon and insulin levels, while in response to the meal at pH 7 only glucagon rose significantly. This was not altered in chemically sympathectomized dogs, nor during the infusion of indomethacin. In all experiments gastrin or gastric glucagon release in response to the meal at pH 2 was either lower than or similar to the response to the meal at pH 7. These data suggest that the influence of the stomach upon islet cell function and glucose homeostasis does not depend on either adrenergic innervation or the presence of prostaglandins, but rather is mediated by a yet undetermined mechanism.
THE MECHANISM OF THE ACID ACTIVATION OF RABBIT UTERINE RENIN
Authors: Jørgensen Jørgen 
Published: December 2008

ABSTRACT
Besides active renin an inactive form of renin could be demonstrated in uterine tissue. On gel filtration it was eluted as a molecule of slightly higher molecular weight than active renin, and it could be irreversibly activated by acidification at 37°C. The activation had a pH optimum between pH 3.8 and pH 5.3. Acid activated uterine renin was found identical to active uterine renin by 1) the formation of angiotensin I with time after addition of rat substrate, 2) the pressor response in the rat, 3) neutralization by antirenin and 4) similar Michaelian constants. Repeated freezing and thawing, acidification at 4°C and dialysis against 4 mol/l NaCl did not give any activation. A lower rate of activation of diluted samples and activation by trypsin at pH 7.4 suggest that proteolytic enzymes are involved in the activation.