bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of lithium chloride on testicular steroidogenesis and gametogenesis in immature male rats
Authors: Ghosh P. K. , Biswas N. M. , Ghosh D. 
Published: June 2009

Abstract.
The present study was performed on immature male rats aged 35 days. Subcutaneous injections of lithium chloride at a daily dose of 2.0 mg/kg for 15 days resulted in significant inhibition of spermatogenesis at stage VII of the seminiferous epithelial cycle. Spermatogonia A, preleptotene spermatocytes and step 7 spermatids were decreased in number in comparison to controls. Serum levels of FSH, LH, PRL, and testosterone were decreased. Activities of testicular Δ5-3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase were suppressed along with a low caudal epididymal sperm count in comparison with controls. When the treatment was prolonged for 20 and 25 days, it showed an additional significant diminution in accessory sex organ weights and number of midpachytene spermatocytes at stage VII in comparison to control animals of corresponding age. It is concluded that lithium has an adverse effect on testicular function in immature rats by reducing serum levels of FSH, LH, PRL, and testosterone. Furthermore, since hormonal changes and altered spermatogenic activities were evident when the serum concentration of lithium was within the therapeutic range, our data may have some potential clinical implications.
Effects of triiodothyronine, dexamethasone and estradiol-17β on GH mRNA in rat pituitary cells in culture as revealed by in situ hybridization
Authors: Martinoli M. G. , Veilleux R. , Pelletier G. 
Published: June 2009

Abstract.
The GH lines of rat pituitary tumour cells have been largely used to study the regulation of GH mRNA. In order to investigate the role of T3, dexamethasone and estradiol-17β on GH expression in non-tumoural pituitary cells, we have used in situ hybridization techniques performed on rat anterior pituitary cells in monolayer culture. The amounts of mRNA encoding for GH, as evaluated by counting the number of grains per somatotrope, were markedly reduced after 4 days of culture in a steroid-free medium supplemented with an hypothyroid calf serum. Addition of T3 or dexamethasone for 3 days increased GH mRNA levels. The concomitant administration of the two hormones produced a synergistic effect on GH mRNA levels which became higher than those observed after T3 or dexamethasone administration alone. However, this effect did not restore GH mRNA levels to those measured in monolayer pituitary cells grown in medium containing 10% fetal calf serum. Moreover GH mRNA levels appeared higher in male than in female pituitary cells. The administration of E2 to pituitary cell cultures from both male and female rats produced an increase by 15, and 12.8% in GH mRNA levels in male and female, respectively. This stimulatory effect of E2 in cell culture was competitively blocked by simultaneous incubation with the antiestrogen LY156758 (Keoxifene). These results demonstrate that T3, dexamethasone as well as E2 act directly on somatotropic cells to regulate GH gene expression.
Sexual dimorphism in renal function and hormonal status of New Zealand genetically hypertensive rats
Authors: Ashton N. , Balment R. J. 
Published: June 2009

Abstract.
Renal water and electrolyte handling and related plasma hormone levels were measured in male and female New Zealand genetically hypertensive and normotensive rats, in an attempt to etablish any potentially important sex-related differences in these parameters. Male hypertensive rats had higher blood pressure than female hypertensive rats, but normotensive rats showed no such sex difference. Both groups of males had higher fluid turnover rates than respective females, and this was associated with raised plasma vasopressin in hypertensive males. Female hypertensive rats excreted more sodium, potassium and chloride in association with lower plasma aldosterone and higher corticosterone levels compared with the other groups. Plasma electrolytes did not differ between the four groups, but plasma osmolality was higher in hypertensive than normotensive rats of both sexes. A higher rate of electrolyte loss and lower fluid turnover in association with reduced plasma vasopressin may contribute to the lower blood pressure of female compared with male hypertensive rats.
Enzymatic deglycosylation of porcine thyroid peroxidase: effects on catalytic activity and immunoreactivity
Authors: Moura Egberto G. , Pazos-Moura Carmen C. , Yokoyama Naokata , Dorris Martha L. , Taurog Alvin 
Published: June 2009

Abstract
Thyroid peroxidase is a heme-containing, membrane-bound, glycoprotein enzyme that catalyzes iodination and coupling in the thyroid gland. It is also the antigen for microsomal autoantibodies that are commonly found in the serum of patients with autoimmune thyroid disease. We examined the effect of deglycosylation on the catalytic functions and the immunoreactivity of this enzyme. A highly purified, solubilized, large tryptic fragment of porcine thyroid peroxidase, retaining all of the N-linked glycosylation sites of the native enzyme and displaying full catalytic activity was used. It was deglycosylated by treatment with N-glycanase under nondenaturing conditions. The loss in relative molecular mass after treatment, determined by gel electrophoresis, was about 75% of the estimated molecular weight of the glycan portion of porcine thyroid peroxidase. Lectin blots performed with horseradish peroxidase-conjugated concanavalin A showed a similar loss in relative molecular mass but some residual carbohydrate. The intensity of the carbohydrate stain was consistent with the loss of about 75% of the glycans. Despite this loss, three different assays for catalytic activity of porcine thyroid peroxidase were not significantly decreased. Immunoreactivity measured by immunoblotting and by enzyme-linked immunosorbent assay was also unimpaired. These findings suggest that N-glycanase-sensitive glycans in porcine thyroid peroxidase do not act as antigenic determinants and play a minor role, if any, in catalytic activity and, presumably therefore, in the maintenance of protein conformation.
Anti-triiodothyronine autoantibodies in a euthyroid woman: Confirmation of immunoglobulin G antibodies employing protein A column chromatography
Authors: Sugenoya Akira , Mizuno Emiko , Haniuda Masayuki , Fujimori Minoru , Masuda Hiroyuki , Kasuga Yoshio , Kobayashi Shinya , Iida Futoshi 
Published: June 2009

Abstract.
The presence of thyroid hormone autoantibodies was investigated in a 48-year-old non-goitrous woman with high levels of serum total T3 and free T3. Her other thyroid function tests were normal. The presence of thyroid hormone autoantibodies were assessed in serum, acid-charcoal treated serum, IgG fractions and in a purified IgG fraction. The IgG fraction was separated from serum by a protein A-Sepharose CL-4B column chromatography and purified by gel filtration chromatography using Sephacryl S 200. Sera from normal individuals were used as controls. The results showed that the increased serum total and free T3 levels were caused by the presence of anti-T3 IgG autoantibodies. The results also indicate that protein A column chromatography is useful as a screening method for gross qualitative analyses of thyroid hormone autoantibodies.
Growth hormone secretion patterns in relation to LH and estradiol secretion throughout normal female puberty
Authors: Wennink Johanna M.B. , de Waal Henriette A. Delemarre-van , Schoemaker Rik , Blaauw Gert , van den Braken Caro , Schoemaker Joop 
Published: June 2009

Abstract.
Pulsatile growth hormone secretion patterns were studied in relation to luteinizing hormone and estradiol release in 33 healthy (pre)pubertal girls. Plasma GH was determined every 10 min, plasma LH and E2 every hour. Night-time GH release was always higher than daytime GH release. During daytime, all GH secretion parameters, except for the basal GH level, increased significantly from the prepubertal stage to stage B4 before (m−) the menarche (p=0.05) and decreased thereafter (p=0.05). During night-time, mean GH level and the fraction of GH in pulses also tended to increase from stage B1 to stage B4m−. The number of high pulses (>8 μg/l) during day and night together tended to increase until stage B4m− and decreased after the menarche (p=0.05). Height velocity did not correlate with the number of high pulses (Kendall τ=0.14, p=0.14). From stage B1 to B4m− high correlations were observed between E2 levels and GH secretion parameters, particularly during the day (τ=0.59-0.71, p≤0.01). The correlations between LH levels and GH secretion were high as well (τ=0.50-0.81, p≤0.01), but equal during day and night. It is concluded that during puberty 1. spontaneous GH release in girls increases 2-3 fold until the menarche and decreases thereafter, primarily as the result of an increasing and decreasing GH pulse amplitude; 2. diurnally increasing estradiol levels correlated with increasing GH secretion.
Diagnostic relevance of suppressed basal concentrations of TSH compared with the negative TRH test in detection and exclusion of hyperthyroidism
Authors: Roden Michael , Nowotny Peter , Vierhapper Heinrich , Waldhäusl Werner 
Published: June 2009

Abstract.
To evaluate the sensitivity of basal TSH concentrations as determined by an "ultrasensitive" IRMA-assay (RIA-gnost h-TSH-monoclonal, Behring) versus a "negative" TRH test (defined as an increment of TSH ≥0.2 mU/l 20 min after administration of 400 μg TRH iv) in the diagnosis of hyperthyroidism we examined 193 consecutive patients from our thyroid outpatient clinic: 34 patients displayed hyperthyroidism (total T4: 184.4±26.0 μmol/l, effective thyroxine index: 1.25±0.08), whereas 12 had isolated T3-hyperthyroidism (total T3: 3.47±0.48 nmol/l). Employing the producer's definition of subnormal ("suppressed") bTSH concentrations (≤0.1 mU/l), only 19 (41.3%) hyperthyroid patients would have been detected; on the other hand, one euthyroid patient would have been recognized false positively as hyperthyroid. Using the TRH test as criterion led to the correct diagnosis in 42 (sensitivity: 91.3%) hyperthyroid patients, whereas two had low bTSH concentrations (≤0.5 mU/l), but a normal TSH response to TRH (>2.0 mU/l). Raising the threshold concentration to 0.2 and, subsequently, to 0.4 mU TSH/l increased the number of correct results to 38 (sensitivity: 82.6%) and 43 (93.5%), respectively. This was associated with a concomitant decrease in specificity in the diagnosis of hyperthyroidism from 93.7 (0.1 mU/l) to 27.9% (0.4 mU/l). In conclusion, despite ultrasensitive methods for estimation of low TSH concentrations, the TRH test remains an irreplaceable tool for the correct diagnosis of hyperthyroidism.
Hyperthyroidism and thyroid carcinoma
Authors: Ahuja S. , Ernst H. 
Published: June 2009

Abstract.
Twenty-two of 251 patients with differentiated thyroid carcinoma suffered from or had a history of hyperthyroidism. They were hyperthyroid with a diffuse goitre (N=4), a diffuse goitre with a cold nodule (N= 10), a multinodular goitre (N=6), and an autonomous adenoma (N=2). Among the 22 patients, more than one fourth had an occult thyroid carcinoma with a diameter of 1 cm or less, those with the papillary tumour types, less frequently had lymph node metastases than the total group of patients with papillary carcinomas (13.3 vs 35.6%). The clinical courses of the 22 patients resembled those of the other thyroid carcinoma patients whose age and initial findings were comparable. In 643 patients who underwent surgery for hyperthyroidism the incidence of thyroid carcinoma was 2.3%. The increase in coincidence of hyperthyroidism and thyroid carcinoma repeatedly reported in recent years is probably ascribable primarily to extensive and improved diagnostics and not to a direct connection between hyperthyroidism and development of thyroid carcinoma. On the other hand, our findings do confirm that, even in the presence of hyperthyroidism, all thyroid nodules require careful diagnostics for exclusion of malignancy.
Blood lymphocyte population following 131I treatment for hyperthyroidism
Authors: Blomgren Henric , Wasserman Jerzy , Petrini Björn , von Stedingk Lars-Viktor 
Published: June 2009

Abstract.
A number of immunological parameters have been monitored for up to 6 weeks following 131I treatment for hyperthyroidism in Graves' disease. The aim was to examine whether this isotope treatment normalizes or further accentuates some immunological abnormalities which may be a manifestation of autoimmune reactions in these patients. It was confirmed that both the cellular composition and immunological reactivities of the patients' blood lymphocytes were abnormal before treatment. After 131I administration a slight lymphopenia occurred and the ratio between CD4 and CD8 positive T lymphocytes (helper-inducer/suppressor-cytotoxic), which was increased before treatment, increased further. Moreover, PWM-triggered IgM secretion in vitro was reduced by 50%. No other immunological parameters studied, such as secretion of other Ig classes, mitogenic responses of lymphocytes, and distribution of other lymphocyte subsets, changed to any detectable extent. It remains speculative whether the 131I-induced changes of the immune system may further accelerate the underlying autoimmune disease processes.
Persistence of altered metabolic responses to beta-endorphin after normalization of body weight in human obesity
Authors: Giugliano Dario , Cozzolino Domenico , Torella Roberto , Lefebvre Pierre J , Franchimont Paul , D'Onofrio Felice 
Published: June 2009

Abstract.
The responses of plasma glucose, insulin, C-peptide and glucagon to an infusion of human β-endorphin (0.5 mg/h) were studied in 10 formerly obese subjects who had lost 35 kg by dieting (body mass index <25) and compared with those of 10 normal-weight control (body mass index <25) and 10 obese (body mass index >30) subjects. The fasting plasma concentrations of β-endorphin were significantly higher in both the obese and the post-obese group than in the control group. In both obese and post-obese subjects, the infusion of β-endorphin caused significant increases in peripheral plasma glucose, insulin, C-peptide and glucagon concentrations. In the control group, matched for age, sex and weight with the formerly obese group, there was no appreciable change in plasma insulin and C-peptide concentrations during the infusion of β-endorphin, but the rise in plasma glucose was more sustained. Thus, 1. the increased plasma β-endorphin concentrations found in human obesity are not corrected by normalization of body weight; and 2. formerly obese, normal-weight subjects behave as obese subjects in their metabolic and hormonal responses to β-endorphin infusion. The alteration of the opioid system in human obesity may play some role in the predisposition to weight gain.
Free thyroxine and 3,3',5'-triiodothyronine levels in cerebrospinal fluid in patients with endogenous depression
Authors: Kirkegaard Carsten , Faber Jens 
Published: June 2009

Abstract.
Total and free concentrations of T4 and rT3 in serum and cerebrospinal fluid were estimated by ultrafiltration in 12 patients with unipolar endogenous depression before and after electroconvulsive treatment. Recovery from depression resulted in a decrease in CSF concentrations of free T4 (median) (26.2 to 21.4 pmol/l, p<0.02) and free rT3 (14.1 to 12.3 pmol/l, p<0.05). Concentrations of free T4 in the cerebrospinal fluid were lower than those in serum (p<0.02), the ratio being 0.6. In contrast, levels of free rT3 in the cerebrospinal fluid were considerably higher than those found in serum (p<0.01), the ratio being 25. These ratios did not change following recovery from depression. In 9 patients with nonthyroidal somatic illness, concentrations of free T4 and rT3 in the cerebrospinal fluid were similar to those found in patients with endogenous depression, whereas 4 hypothyroid patients and one hyperthyroid patient had considerably lower and higher, respectively, concentrations of both free T4 and rT3. In conclusion, levels of free T4 and free rT3 in the cerebrospinal fluid are increased during depression compared with levels after recovery, probably reflecting an increased supply of T4 from serum and an increased production of rT3 from T4 in the brain. The data also suggest that the transport of iodothyronines between serum and the cerebrospinal fluid is restricted.
Mechanism of thyroid stimulation by human chorionic gonadotropin in sera of normal pregnant women
Authors: Yoshimura Masayoshi , Nishikawa Mitsushige , Yoshikawa Norio , Horimoto Masateru , Toyoda Nagaoki , Sawaragi Isamu , Inada Mitsuo 
Published: June 2009

Abstract.
To elucidate the mechanism of thyrotropic activity of human chorionic gonadotropin in sera of normal pregnant women, we examined the effect of blockade of the TSH receptor on the serum-induced cAMP accumulation and the effect of hCG on the TSH binding to FRTL-5 cells. In the presence of crude immunoglobulin fractions in sera from patients with primary hypothyroidism, cAMP accumulation induced by both crude and purified hCG, and normal pregnant women serum were significantly inhibited compared with that in the presence of normal IgGs. The mode of inhibition of these IgGs on the cAMP accumulation was similar for TSH and hCG when analysed by Lineweaver-Burk plots. Moreover, binding of [125I]TSH to the TSH receptor in porcine thyroid cell membrane was apparently inhibited by adding 4×106 IU/l of purified hCG. Binding studies of TSH in FRTL-5 cells also indicated the dose-dependent displacements of [125I]TSH by hCG. Although half-maximal inhibitory- concentration of hCG was about 20 times as high as that of TSH on a molar basis, displacement of [125I]TSH was observed at a concentration of hCG of 105IU/l or more, which could be a physiological concentration of hCG in sera of normal pregnant women. These results suggest that thyrotropic activity of hCG in sera of normal pregnant women is, at least in a part, mediated by TSH receptors.
Autonomous progesterone secretion from the bovine corpus luteum in vitro
Authors: Rossmanith Winfried G. , Schick Markus , Benz Reiner , Lauritzen Christian 
Published: June 2009

Abstract.
While the regulation of progesterone secretion from the corpus luteum by LH has been convincingly demonstrated, the secretory patterns in the absence of any pituitary LH inputs are yet unclear. Consequently, we investigated the progesterone secretion by an in vitro perifusion system to characterize spontaneous progesterone release from the isolated bovine corpus luteum. Slices (120 mg) of midluteal corpora lutea were placed in perifusion chambers and continuously perifused by Medium-199 for 160-320 min. Progesterone was determined by radioimmunoassay in the effluent fractions collected at 2-min intervals. The spontaneous progesterone release from all bovine corpora lutea was pulsatile. Pulses were observed at mean (±sem) intervals of 17.7±1.5 min with amplitudes of 6.7±0.5 ng and release rates of 29.5±2.4 ng · ml−1 · (2 min)−1 (N=5). Addition of 6.7 nmol/l hCG to the perifusion medium appeared to increase the pulse amplitudes and release rates (195±25% over unstimulated conditions), but did not change the pulse frequencies (N=3). Perifusions with calcium-free medium containing 50 μmol/l verapamil and 20 mmol/l EGTA tended to suppress the pulse frequencies and amplitudes of this spontaneous progesterone release, whereas addition of hCG reversed this decrease again (N=3). When prostaglandin activity was inhibited by 100 μmol/l indomethacin added to the perifusion medium, both pulse frequencies and amplitudes of this progesterone release were enhanced (N=4). During perifusions with 100 μmol/l of the anti-progesterone ZK 96.734, both the pulse frequencies and amplitudes increased (N=4). These studies demonstrate an episodic progesterone release from the bovine corpus luteum perifused in vitro. The spontaneous progesterone secretion is independent of, but facilitated by gonadotropin secretion. This pulsatile progesterone secretion from the midluteal corpus luteum and its regulation by intraovarian factors may reflect an autonomous pulse generating mechanism.
Transient increase in renal epidermal growth factor content after unilateral nephrectomy in the mouse
Authors: Kanda Shigeru , Saha Pabitra K. , Nomata Koichiro , Taide Masakatsu , Nishimura Naoki , Igawa Tsukasa , Yamada Jun , Kanetake Hiroshi , Saito Yutaka 
Published: June 2009

Abstract.
A sensitive enzyme-linked immunosorbent assay for mouse epidermal growth factor was established for measurement of the content of epidermal growth factor in the remaining kidney after uninephrectomy. In 5-week-old male mice, the renal epidermal growth factor content before uninephrectomy was 355±97 ng/g wet tissue with a 2.1-fold increase on the first day after uninephrectomy, whereafter it gradually decreased. In 15-week-old mature male mice, the renal epidermal growth factor content increased 1.7-fold on the first day after uninephrectomy. Immunohistochemical analysis showed that epidermal growth factor was present in the distal tubular cells and that the staining intensity was increased on the first day after uninephrectomy. During the course of compensatory renal growth, no significant alteration of epidermal growth factor content was observed in plasma or in the submaxillary gland. Our data suggest that the increase in renal epidermal growth factor content after uninephrectomy is due to an increased production of epidermal growth factor in the kidney itself. The significance of this phenomenon is discussed.
Objective assessment of concordance of secretory events in two endocrine time series
Authors: Guardabasso Vincenzo , Genazzani Alessandro D. , Veldhuis Johannes D. , Rodbard David 
Published: June 2009

Abstract.
A new objective method is presented for investigating the presence of a temporal relationship between episodic release of two hormones. The two time series of hormone concentrations are first analysed by an objective method for peak detection. Both data series are then transformed into "quantized" or discretized series by recording the occurrence of a hormone pulse as an "event", characterized by the onset, the maximum, or another unique feature. The two quantized series are then matched, and the number of concordant events and discordant events are counted. Each point in series A is compared with a "time-window" of a selected number of points in series B, to accommodate small degree of mismatch between events in the two series. An index of concordance is computed, compensating for any spurious random coincidence: the "Specific Concordance", to evaluate the frequency of concordant events in excess of those expected on the basis of chance alone. This calculation is systematically repeated, interposing a range of time-lags between the two series. A graph of Specific Concordance versus time-lag indicates the time-lag corresponding to a maximal concordance. Simulations of random series of events are performed, and their degree of concordance is evaluated in a similar fashion, thus generating frequency distributions of Specific Concordance values under the null hypothesis of no temporal relationship. This permits the selection of criteria for statistical significance at any desired p-level, for one or many lag times, and for one or multiple subjects. Various degrees of concordance can also be simulated to evaluate the performance (sensitivity, statistical power) of this approach. These methods have been implemented as a collection of short microcomputer programmes, and applied to the study of the temporal relationship between β-endorphin and cortisol in normal subjects sampled every 10 min for 24 h. This analysis demonstrated concordance between events in the two series, with synchronous occurrence of β-endorphin and cortisol release events significantly more frequently than expected on the basis of random association (p<0.01).