bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clomiphene stimulation test in men with idiopathic hypospermatogenesis
Authors: Johnsen Svend G. 
Published: December 2008

Abstract.
A standardized clomiphene stimulation test with assay of serum FSH, LH, testosterone and oestradiol and urinary androsterone + aetiocholanolone, dehydroepiandrosterone and total oestrogens was applied to 23 men with idiopathic hypospermatogenesis as compared with 12 normal controls. In the patients the percentual rise of LH was increased and the percentual rises of testosterone and oestradiol decreased as compared with controls. The study thus showed that abnormalities in the testicular steroid producing apparatus exist in hypospermatogenesis and could be the cause of the spermatogenetic failure. It was further showed that the reserve capacity of the testicular steroid production is highly limited in contrast to the large reserve capacity of gonadotrophin production in the hypophysis.
Serum prolactin and thyrotrophin responses to thyrotrophin-releasing hormone at different times of the day in normal women
Authors: Pérez-López F. R. , Gómez G. , Abós M. D. 
Published: December 2008

Abstract.
In order to determine whether or not the pituitary responsiveness to thyrotrophin-releasing hormone (TRH) changes during the nyctohemeral cycle, 10 healthy regularly cycling women were given 200 μg of TRH at 02.00 h, 10.00 h and 18.00 h with at least a 32 h interval between each test. Serum prolactin (Prl) and thyrotrophin (TSH) in 7 of the 10 women were measured serially before and after TRH administration. The mean basal Prl levels were significantly higher (P < 0.01) at 02.00 h than at 10.00 h and 18.00 h. The mean basal TSH levels were higher, although not significantly, at 02.00 h than at 10.00 h and 18.00 h. Although a higher TSH release occurred at 02.00 h than at 10.00 h and 18.00 h, the mean serum TSH and Prl peak responses to TRH were statistically similar in the three groups of tests. The integrated changes scores, calculated as the difference between the average post-TRH hormonal release and the average baseline levels, although higher in the 18.00 h test for Prl and the 02.00 h test for TSH, were not statistically different among the three tests.
Iliac crest bone mass and remodelling in acromegaly
Authors: Halse Johan , Melsen Flemming , Mosekilde Leif 
Published: December 2008

Abstract.
Iliac crest bone biopsies from 18 patients with active acromegaly, of whom 11 had received tetracycline double-labelling, were evaluated by quantitative histomorphometry and compared with age- and sex-matched normal controls. A significant increase (P < 0.01) was found in both cortical (175%) and trabecular (130%) bone mass. In trabecular bone, resorption surfaces and active (tetracycline-labelled) and total formation surfaces were increased (P < 0.05 and P < 0.01, respectively) causing an enhanced bone turn-over at tissue level (P < 0.01). The increased trabecular bone mass indicates a positive net balance per remodelling cycle and, therefore, larger than normal bone remodelling units, which in part may explain the increased bone turn-over at tissue level. The activity of the osteoblasts active in mineralization (the appositional rate) was increased (P < 0.01) and positively related to the fasting serum growth hormone levels (Rs = 0.69, P < 0.05). The average activity of active and inactive osteoblasts (bone formation rate at basic metabolic unit (BMU) level) was insignificantly increased. The proportion of active (tetracycline labelled) to non-active formation surfaces was normal. The bone changes were unrelated to serum levels and urinary excretions of calcium and phosphorus or to renal excretion of total and non-dialyzable hydroxyproline or cAMP.
HLA-A, -B, -C and -DR antigens in patients with Graves' disease and their correlation with signs and clinical course
Authors: Dahlberg P. A. , Holmlund G. , Karlsson F. A. , Säfwenberg J. 
Published: December 2008

Abstract.
Among 78 consecutive patients with Graves' disease, an increased frequency of HLA-B8 and HLA-DR3 antigens was found. The relative risk for Graves' disease among individuals with these HLA antigens was calculated as 4.4 and 3.9, respectively. Thus, genes promoting the development of Graves' disease are clearly associated to the B8 and DR3 haplotypes. In groups of patients with different clinical expressions of the disease, such as thyroid hormone levels, autoantibodies and relapse rates, the frequency of B8 and DR3 antigens was found to be similar. Consequently, factors influencing the clinical expression and the course of the disease do not have a stronger association to these antigens.
Effects of graded doses of triiodothyronine on TSH synthesis and secretion rates in hypothyroid rats
Authors: Lemarchand-Béraud Th. , Berthier C. 
Published: December 2008

Abstract.
The effects of a graded low dose of T3 on plasma TSH, anterior pituitary TSH content (AP-TSH) and on TSH synthesis and secretion rates, were studied in adult male rats previously treated for 7 days with 0.01% prophylthiouracil (PTU). Pituitary TSH content, plasma T3, T4 and TSH levels were measured by RIA at 0, 6, 12, 24 h after the injection of T3 ranging from 0.1 to 0.75 μg/100 g b.w. Saline treated normal rats served as control. The 7-day PTU treated rats displayed low but still detectable thyroid hormone plasma levels; high plasma TSH levels were observed, but with no further increase after TRH injection as the AP-TSH content was depleted. Injections of T3 increased plasma T3 in proportion with the dose given. Plasma T4 remained low and there was no significant decrease in plasma TSH until doses of 0.2 μg/100 g b.w. T3 was given. Then the transient TSH depression was dose-dependent from 0.2 to 0.75 μg/100 g b.w. The AP-TSH content increased regularly from 0.2 μg/T3 onwards, overlapping the transient inhibition of TSH secretion resulting in a 3-fold increase in the AP-TSH content, suggesting a positive action of T3 on TSH synthesis. In addition, TSH response to TRH was observed at every time studied after T3 injection. Then, the different groups were injected with [125I]rTSH in order to estimate metabolic clearance rates, TSH secretion and synthesis rates.
The half-life of [125I]rTSH (22 min) and its metabolism clearance rates (16 ± 0.4 ml/h/100 g b.w.) were found similar in all groups. Whereas the TSH secretion rates was highly reduced in the normal rats receiving 0.3 μg T3 (156 ± 9 vs 408 ± 22 μg/24 h in normal rats), the PTU group displayed a 3-fold increased secretion rate (1222 ± 44 μg/24 h) which was not modified by the injection of 0.1–0.2 μg T3 and decreased to 868 and 472 μg/24 h with 0.3 μg and 0.75 μg T3, respectively. TSH synthesis rates were found highly increased in the PTU group (1222 ± 44 μg/d vs 408 ± 22 μg/d in normal rats) and was neither increased nor reduced in the 7-day PTU rats receiving 0.1–0.3 μg T3 but a slight reduction was observed only in the 0.75 μg T3 group.
These data show that 0.1–0.2 μg/100 g b.w. T3 changed neither TSH secretion nor its synthesis rates while 0.3 μg more or less a replacement dose inhibited TSH secretion without changing TSH synthesis rates, resulting in a AP-TSH replenishment. Therefore, no direct positive effect of low doses of T3 on TSH synthesis could be demonstrated over 24 h while higher doses are capable of inhibiting first secretion and then synthesis of TSH.
The influence of vitamin D intake on serum calcium in tuberculosis
Authors: Gwinup Grant , Randazzo Guy , Elias Alan 
Published: December 2008

Abstract.
We report the first prospective controlled study designed to determine the effect of vitamin D ingestion on serum calcium concentration in patients with tuberculosis. Every patient admitted to the tuberculosis ward over a 6 month period, who was free of any condition which might influence serum calcium concentration, was randomly assigned to one of two groups. The diet of the first group was substituted with ergocalciferol 5000 units daily. The diet of the second group was not supplemented. In addition, the second group was randomly subdivided into two subgroups. The first subgroup received a diet unrestricted in vitamin D. The second subgroup received a diet containing less than 50 units of vitamin D. Serum calcium was determined at weekly intervals. In contradistinction to the results of a previously reported retrospective study, there was no significant difference between the group receiving supplemental vitamin D and the control group at any time during the entire period of study. Furthermore, there was no significant difference between the subgroup of patients receiving normal dietary vitamin D and the sungroup maintained on the diet restricted in vitamin D.
Serum levels of testosterone, cortisol, prolactin and bioactive luteinizing hormone in adult male rhesus monkeys following cage-restraint or anaesthetizing with ketamine hydrochloride
Authors: Puri C. P. , Puri V. , Kumar T. C. Anand 
Published: December 2008

Abstract.
The present studies were carried out to characterize and compare the acute effects of cage-restraint or administration of a mild anaesthetic on serum levels of testosterone (T) cortisol (C), prolactin (Prl) and bioactive luteinizing hormone (LH) in adult male rhesus monkeys. Serum T levels declined progressively while C levels increased in the 3 sequential blood samples obtained at 20 min intervals from restrained monkeys. Prl and LH levels in the serum remained unaltered. Following single or multiple injections of ketamine hydrochloride (10 mg/kg) serum T levels did not decline progressively as seen in the blood samples obtained from the cage-restrained, conscious monkeys. Serum C and Prl levels showed a progressive rise following anaesthetization. LH levels were not affected by the anaesthetic. The findings reported here are of pertinent relevance to the evaluation of acute effects of any experimental procedure aimed at altering circulating levels of the hormones studied.
A sensitive bioassay for luteinizing hormone-like activity applied to systemic plasmas of foetal rats
Authors: Picon Régine , Habert René 
Published: December 2008

Abstract.
A sensitive bioassay for plasma LH-like activity has been developed by utilization of the testosterone response of foetal rat testes to gonadotrophic stimulation in vitro. The volume of plasma required for the assay and the target organ make the method suitable for bioassays of circulating LH-like activity in foetal rat plasma. When applied to foetal plasmas, the method has shown that castration performed on day 19 of gestation induced 24 h later an increase in the LH-like activity of the plasma and that decapitation under the same conditions led to a decrease in this activity in male foetuses.
Treatment of maternal hyperthyroidism with antithyroid agents and changes in thyrotrophin and thyroxine in the newborn
Authors: Lamberg B.-A. , Ikonen E. , Teramo K. , Wägar G. , Österlund K. , Mäkinen T. , Pekonen F. 
Published: December 2008

Abstract.
Eleven pregnant women with concomitant hyperthyroidism were treated with antithyroid drugs. At monthly intervals serum thyroxine (T4) and triiodothyronine (T3) were measured with radioimmunoassay, the Sephadex uptake of radioactive triiodothyronine (T3U) determined and the free T4 and T3 indices calculated (FT4I, FT3I). TSH-binding inhibiting immunoglobulins (TBII) were determined by the radiomembrane assay. Serum TSH and T4 were measured at delivery from cord blood and/or from the newborn infants some days after birth.
Serum TSH was significantly elevated in one infant. There was an inadequate post-partal rise in serum T4 concentration in this child and in another who showed only a marginal elevation of TSH. The mothers of these infants were given carbimazole in doses of 30 and 25 mg/day, respectively, at the time of delivery. No significant changes were seen in other infants, the daily doses being 20 mg of carbimazole or less. There was no clinical indication of hypo- or hyperthyroidism in any of the newborn.
The TBII were positive in most patients and there was a trend of normalization during treatment. No relationship between the dose of antithyroid drug and the level of TBII could be seen. During treatment the dose was adjusted according to the FT3I values. This seems to be an adequate laboratory test for this purpose.
Effect of epinephrine and 5-hydroxytryptamine on in vitro thyroid iodine organification
Authors: Masini-Repiso Ana María , Coleoni Aldo Héctor 
Published: December 2008

Abstract.
The effect of epinephrine (E) and 5-hydroxytryptamine (5-HT) on some elements involved in thyroid iodine organification was studied using a bovine thyroid subcellular fraction sedimented at 30 000 g. 131I-incorporation into particulate proteins and into tyrosine was increased by 10−3 m and 10−5 m E and 5-HT. This effect was inhibited by 6-n-propyl-2-thiouracil and by catalase.
In the presence of these amines the activity of NADPH-cytochrome c reductase was not modified. Both E and 5-HT were able to generate H2O2 when added to the particulate fraction as measured by the oxidation of o-dianisidine. H2O2 generation and [131I]iodotyrosine formation were inhibited by pargyline, a monoamine oxidase (MAO) inhibitor. Tyramine, a specific substrate for thyroid MAO, produced H2O2 and increased [131I]iodotyrosine formation. This effect was higher when compared to the effect elicited by E or 5-HT. The stimulatory effects of tyramine were blocked by pargyline. The action of tyramine on H2O2 generation and [131I]iodotyrosine formation was diminished when E or 5-HT were incorporated to the system.
From these results it is suggested that E and 5-HT serving as MAO substrates would generate H2O2 and in this way increase the thyroid iodine organification. On the other hand, these amines would be able to reduce the increased H2O2 generation induced by tyramine and thus decrease the iodination process. These findings could explain the stimulatory or inhibitory effects of biogenic amines on thyroid function which are dependent on the previous thyroid activity.
The disappearance of l-thyroxine and triiodothyronine from plasma and red and white skeletal muscle after administration of one sc dose of l-thyroxine to hyperthyroid and euthyroid rats
Authors: Janssen J. W. , de Lange-Berkhout I. W. L. , van Hardeveld C. , Kassenaar A. A. H. 
Published: December 2008

Abstract.
Rats were made hyperthyroid by repeated sc injections of l-thyroxine (T4) in a two-week period. At several time-points after the last injection, the triiodothyronine (T3) and T4 concentrations in plasma and red and white skeletal muscle were determined by a radioimmunoassay. This was done to investigate the relationship between the change in thyroid-hormone concentration in plasma and muscle and to see whether this change was similar in both muscle types. The results show that:
1. Information about the T3 and T4 concentrations in the muscles of the hyperthyroid rats can only be obtained by direct measurement in the muscles and cannot be gathered from the plasma-T3 concentration at any time-point or from below-normal plasma-T4 concentrations.
2. In hyperthyroid rats T4 and T3 are cleared more rapidly from the plasma than from the skeletal muscle.
3. A proportionally higher T3 concentration is present in the red compared with the white skeletal muscle of hyperthyroid rats.
Gonadotrophin release by gonadotrophs incubated with gonadotrophin-releasing hormone is independent of intracellular cAMP accumulation
Authors: Benoist L. , Le Dafniet M. , Rotsztejn W. H. , Besson J. , Duval j. 
Published: December 2008

Abstract.
Rat pituitary cells were dispersed with trypsin and separated by sedimentation at unit gravity. The distributions of prolactin (Prl), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were determined, and two enriched cell populations (mammotrophs and gonadotrophs) were subsequently cultured. During a 4 h incubation, gonadotrophin-releasing hormone (GnRH) stimulated the release of LH and of FSH by both the unfractionated population and the enriched gonadotrophs; the magnitude of this stimulation increased with the length of the pre-culture periods, and the amount of LH released into the medium correlated strongly with the amount of FSH, whatever the length of the pre-culture period. The cellular cAMP content was also enhanced during the 4 h incubation, but no correlation was found between the hormone release and the cAMP accumulation. Furthermore, during the first 30 min of incubation with GnRH there was no increase of cellular cAMP, whatever cell population used.
We conclude that the gonadotrophin release was independent of the cAMP accumulation observed in pituitary cells several hours after stimulation by GnRH; consequently, the late increase in the nucleotide is suggested to be a non-specific secondary process.
Prolactin content in rat pituitary gland. RIA of prolactin after different extraction procedures
Authors: Haggi E. , Aoki A. 
Published: December 2008

Abstract.
The prolactin content of rat pituitary varies considerably when determined by RIA, due to incomplete solubilization of prolactin secretory granules with standard procedures for tissue homogenization and centrifugation. Freezing and thawing, Triton X-100 and ultrasonic treatments increased the yield of prolactin significantly but electron microscopy of pellets revealed numerous unmodified secretory granules. Addition of 2.5 m urea produced complete extraction of tissue prolactin confirmed by RIA of supernatants and electron microscopy of pellets.
Micromethod of human thyrocyte cultures for detection of thyroid-stimulating antibodies and thyrotrophin
Authors: Stöckle G. , Wahl R. , Seif F.J. 
Published: December 2008

Abstract.
The activation of adenylate cyclase of human thyrocytes in primary cell cultures and the release of cAMP into the medium are used to detect thyrotrophin (TSH) and thyroid-stimulating antibodies (TSAb) in sera of patients with Graves' disease. Tissue digestion and cell dispersion are performed using a neutral protease of Bacillus polymyxa (Dipase II), which harvests more vital thyrocytes than does trypsin. The cells show an enhanced response to stimulation. The efficeincy of the cell preparation and cultivation is increased by using microtest plates instead of culture flasks. By this minimization only 0.6–1.8 × 106 cells are needed to evalute a single sample. Cyclic AMP concentrations are measured directly in the supernatant culture medium by a competitive protein binding assay with charcoal separation. The minimal detectable dose of bTSH is about 10 μU/ml. With increasing doses of bTSH cAMP concentrations rise to a peak at about 50 to 100 mU/ml, beyond which there is a gradual decrease of cAMP indicating negative cooperativity in the activating mechanisms. The 'long-acting thyroid stimulator' effect of TSAb is reflected by a protracted increase of cAMP to its maximal value. All 41 sera of hyperthyroid patients with Graves' disease were TSAb-positive, whereas sera of patients with toxic nodular goitre and of euthyroid controls were TSAb-negative.
Plasma prolactin and gonadotrophins in anorexia nervosa and amenorrhoea due to weight loss
Authors: Skrabanek P. , Devlin J. , McDonald D. , Powell D. 
Published: December 2008

Abstract.
The role of prolactin in anorexia nervosa is controversial and both hyperprolactinaemia and normoprolactinaemia were reported in patients with anorexia nervosa. We have measured immunoreactive prolactin by radioimmunoassay in plasma samples from 14 consecutive patients with anorexia nervosa and found normoprolactinaemia in 13 patients and a borderline elevation of plasma prolactin in one patient. The mean plasma prolactin level in anorexia nervosa patients did not differ from an age-matched control gorup of patients with amenorrhoea due to simple weight loss. While we were unable to confirm reports on the common occurrence of hyperprolactinaemia in anorexia nervosa, the absence of hyperprolactinaemia suggests a different mechanism of amenorrhoea in patients with anorexia nervosa and due to simple dieting from that in idiopathic secondary amenorrhoea in which the frequency of hyperprolactinaemia is about 30%. The mean plasma follicle-stimulating hormone was abnormally low both in patients with anorexia nervosa and simple weight loss, while the mean plasma luteinizing hormone was depressed only in patients with anorexia nervosa. This difference is compatible with a more profound hypothalamic disorder in anorexia nervosa, which is not solely dependent on the weight loss, than in amenorrhoea due to simple dieting.
Properties of human thyroidal and extrathyroidal TSH receptors
Authors: Trokoudes Krinos M. , Michelsen Harold , Kidd Arthur , Row Vas V. , Volpé Robert 
Published: December 2008

Abstract.
The presence of high affinity receptor sites for thyroid-stimulating hormone (TSH) in the human is not limited to the thyroid gland. In this report, the properties of thyroidal and extrathyroidal TSH binding have been explored through the effect of various agents (TSI of Graves' disease, propranolol, hCG, N-acetylneuraminic acid, ACTH, insulin and L-thyroxine) on the receptors.
Statistically significant inhibition of [125I]TSH binding occurred with all immunoglobulin preparations (TSI) of Graves' disease on thyroid cell membrane receptors. Thirty-three per cent of the same immunoglobulins showed significant inhibition of [125I]TSH binding when testicular cell membranes were used, while there was no such inhibition when renal cell membranes were utilized. D or L-propranolol at least doubled the [125I]TSH initial binding (Bo) to the thyroid membranes but had no effect on the testicular or fat cell binding. Human chorionic gonadotrophin (hCG) at concentrations of 400 USP units per 350 μl totally inhibited the [125I]TSH from binding to testicular membranes but not to thryroid or fat cell membranes. Conversely, the binding of [125I]hCG to human testicular membrane was inhibited by both stable hCG and TSH, but with human thyroid membrane, only TSH could inhibit binding of [125I]hCG. These data suggest that the TSH receptors in extrathyroidal tissues may not be identical to TSH receptors within the thyroid. TSH binding to thyroidal tissue was significantly suppressed by N-acetylneuraminic acid, was increased by D and L-propranolol and was unaffected by ACTH and insulin. L-thyroxine had a dose-related suppressive effect on the TSH binding, commencing at 50 μg/ml. While these effects were observed in vitro, it is possible that some of the above agents may also interfere with thyroid gland function in vivo. They suggest further that a number of interactions may take place at the TSH binding sites which could alter TSH binding and/or function.
Paradoxical effect of perchlorate on thyroidal weight, glucose 6-phosphate dehydrogenase and polyamines in methylthiouracil-treated rats
Authors: Matsuzaki S. , Suzuki M. 
Published: December 2008

Abstract.
The effect of sodium perchlorate (NaClO4) on the methylthiouracil-induced increase in the activity of thyroid glucose 6-phosphate dehydrogenase (G6PDH), ornithine decarboxylase (ODC) and polyamine contents was studied in the rat. The G6PDH activity was increased nearly three-fold by methylthiouracil (MTU) but not by ClO4- at 7 days of treatment. Perchlorate lowered the MTU-induced enzyme activity to nearly the control level, without changing circulating thyrotrophin (TSH). The anion had no inhibitory effect on G6PDH activity in vitro. The possibility that an inhibitor specific for G6PDH was generated in ClO4- treated rat thyroids was excluded.
The activity of ODC was greatly increased by both ClO4- and MTU, the increase being significant as early as on the second day of treatment. Perchlorate had no inhibitory effect on MTU-induced ODC activity in vivo but decreased total contents of spermidine and spermine in the thyroid, without affecting the concentration (nmoles/ g wet weight) of the polyamines. These results suggest that ClO4- acts directly on the thyroid to suppress specifically the stimulatory effect of TSH on G6PDH activity and possibly on polyamine accumulation.