bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of cytokines and growth factors on the secretion of inhibin A, activin A and follistatin by term placental villous trophoblasts in culture
Authors: Mohan A , Asselin J , Sargent IL , Groome NP , Muttukrishna S
Published: January 2005

OBJECTIVE: Maternal serum inhibin A and activin A are higher in pre-eclampsia than in normal pregnancy. The placenta is a source of these proteins in pregnancy. The aim of this study was to investigate the effect of growth factors and proinflammatory cytokines that are raised in pre-eclampsia on the secretion of dimeric inhibin A, activin A and follistatin by villous cytotrophoblasts in culture. DESIGN AND METHODS: Villous cytotrophoblasts were prepared from term placentae and cultured in serum-free media. Cells were treated with increasing concentrations of tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, transforming growth factor (TGF)-beta1, granulocyte and monocyte colony-stimulating factor (GMCSF), inhibin A, activin A and follistatin for 2 days. Culture supernatants were assayed for human chorionic gonadotrophin (hCG), inhibin A, activin A and follistatin as appropriate. Experiments were repeated at least three times with each cytokine or growth factor and the data pooled. RESULTS: Cytotrophoblasts syncytialise and spontaneously secrete hCG, inhibin A and activin A in culture. Follistatin levels were <20 pg/ml in most experiments. Activin A secretion was increased in culture in a dose-dependent manner by IL-1beta (approximately 150%, P<0.05), TNF-alpha (approximately 35%, P=0.02) and GMCSF (approximately 100%, P<0.01). hCG secretion was inhibited in a dose-dependent manner by TNF-alpha (50%, P<0.05). Inhibin A was stimulated by IL-1beta ( approximately 30%, P=0.05). Inhibin A, activin A, follistatin or TGF-beta1 did not have a significant effect on any measured parameters. CONCLUSIONS: These data show that inflammatory cytokines increase the secretion of activin A by trophoblasts in culture. The presence of very low levels, or no follistatin (<20 pg/ml) in the culture media suggests 'free' activin A could have autocrine/paracrine effects on cytotrophoblasts. Inhibin A secretion was stimulated by IL-1beta. However, absence of an effect by the other cytokines investigated on inhibin A in this study suggests that the mechanism(s) involved in increasing maternal circulating levels of inhibin A and activin A in pre-eclampsia are controlled differentially.
Bisphenol-A, an environmental estrogen, activates the human orphan nuclear receptor, steroid and xenobiotic receptor-mediated transcription
Authors: Takeshita A , Koibuchi N , Oka J , Taguchi M , Shishiba Y , Ozawa Y
Published: January 2005

BACKGROUND: There is increasing concern about endocrine-disrupting chemicals (EDCs) which may produce adverse health effects in humans and other species. One such chemical, bisphenol-A (BPA), a monomer of polycarbonate plastics, is widely used in consumer products; it has been reported to contain estrogenic activity through binding to estrogen receptors. Cytochrome P450 mono-oxygenase 3A4 (CYP3A4) is one of the key enzymes for the metabolism of endogenous steroids and foreign chemicals in liver. The orphan nuclear receptor, steroid and xenobiotic receptor (SXR/PXR), has recently been isolated. A variety of known inducers of CYP3A4 bind to SXR/PXR, and stimulate transcription on xenobiotic-response elements (XREs) located in the promoter region of the CYP3A4 gene. Recent study has shown that EDCs, diethylhexylphthalate (DEHP) and nonylphenol, but not BPA, induce mouse SXR/PXR-mediated transcription. However, it is known that species differences in SXR alter CYP3A inducibility. OBJECTIVE: To test whether BPA stimulates human SXR/PXR-mediated transcription using reporter gene assays. METHODS: Transfection assays were performed with human SXR/PXR expression plasmid and a reporter plasmid containing the XREs in the CYP3A4 gene promoter in HepG2 cells. BPA-induced interaction of human SXR/PXR with steroid receptor coactivator-1 (SRC-1) was analyzed by mammalian two-hybrid assays. RESULTS: BPA, as well as DEHP, activated human SXR-mediated transcription on the XREs. In mammalian two-hybrid assays, BPA recruited SRC-1 to the ligand-binding domain of human SXR/PXR. CONCLUSIONS: Our observations have indicated that BPA may be a human-specific inducer of the CYP3A4 gene, and may influence the metabolism of endogenous steroids, drugs, and other xenobiotics.
Mammary gland development and lactation are controlled by different glucocorticoid receptor activities
Authors: Reichardt HM , Horsch K , Grone HJ , Kolbus A , Beug H , Hynes N , Schutz G
Published: January 2005

OBJECTIVE: Regulation of physiological processes by glucocorticoids is achieved by binding to the glucocorticoid receptor (GR) and subsequent modulation of gene expression, either by DNA binding-dependent mechanisms or via protein-protein interaction with other transcription factors. The purpose of this study was to define the molecular mechanism of GR underlying the control of mammary gland development and lactation. DESIGN: To dissect the mechanism of GR action in the mammary gland, we used genetically modified mice carrying a DNA binding-defective GR. These mice retain the ability to regulate transcription by protein-protein interaction but fail to control gene expression by DNA binding-dependent mechanisms. Thus, they allow the study of the mode of GR action in vivo. METHODS: The development of the mammary gland and milk protein synthesis during lactation were studied using histological and biochemical methods. RESULTS: Our findings demonstrated that the lack of the DNA binding function of GR impairs the ductal development of the mammary gland in virgin females and that this can presumably be accounted for by reduced proliferation of epithelial cells. In contrast, lactating females have normally differentiated mammary glands and are fully capable of milk protein production. This is in good agreement with the demonstration that the DNA binding-defective GR is still able to interact with phosphorylated Stat5 proteins, suggesting that transcriptional regulation by protein-protein interaction forms the basis of glucocorticoid action in this process. CONCLUSIONS: The present study has demonstrated that GR plays an important role in the mammary gland and that it uses different molecular modes of action to control development and milk protein synthesis.
G protein mutations in endocrine diseases
Authors: Lania A , Mantovani G , Spada A
Published: January 2005

This review summarizes the pathogenetic role of naturally occurring mutations of G protein genes in endocrine diseases. Although in vitro mutagenesis and transfection assays indicate that several G proteins have mitogenic potential, to date only two G proteins have been identified which harbor naturally occurring mutations, Gsalpha, the activator of adenylyl cyclase and Gi2alpha, which is involved in several functions, including adenylyl cyclase inhibition and ion channel modulation. The gene encoding Gsalpha (GNAS1) may be altered by loss or gain of function mutations. Indeed, heterozygous inactivating germ line mutations in this gene cause pseudohypoparathyroidism type Ia, in which physical features of Albright hereditary osteodystrophy (AHO) are associated with resistance to several hormones, i.e. PTH, TSH and gonadotropins, that activate Gs-coupled receptors or pseudopseudohypoparathyroidism in which AHO is the only clinical manifestation. Evidence suggests that the variable and tissue-specific hormone resistance observed in PHP Ia may result from tissue-specific imprinting of the GNAS1 gene, although the Gsalpha knockout model only in part reproduces the human AHO phenotype. Activating somatic Gsalpha mutations leading to cell proliferation have been identified in endocrine tumors constituted by cells in which cAMP is a mitogenic signal, i.e. GH-secreting pituitary adenomas, hyperfunctioning thyroid adenomas and Leydig cell tumors. When the same mutations occur very early in embryogenesis they cause McCune-Albright syndrome. Although these mutations would in principle confer growth advantage, studies failed to detect differences in the clinical and hormonal phenotypes, suggesting the existence of mechanisms able to counteract the activation of the cAMP pathway. Activating mutations of Gi2alpha have been identified in a subset of ovarian, adrenal and pituitary tumors, but their prevalence and significance are still controversial. Finally, although Galpha subunits are the only components of the heterotrimeric GTP binding proteins which harbor known mutations, beta/gamma subunits should be considered possible targets of genetic alterations as suggested by the frequent presence of beta3 subunit variants in patients with essential hypertension.
Inhibin B in male reproduction: pathophysiology and clinical relevance
Authors: Meachem SJ , Nieschlag E , Simoni M
Published: January 2005

The recent availability of specific inhibin assays has demonstrated that inhibin B is the relevant circulating inhibin form in the human male. Inhibin B is a dimer of an alpha and a betaB subunit. It is produced exclusively by the testis, predominantly by the Sertoli cells in the prepubertal testis, while the site of production in the adult is still controversial. Inhibin B controls FSH secretion via a negative feedback mechanism. In the adult, inhibin B production depends both on FSH and on spermatogenic status, but it is not known in which way germ cells contribute to inhibin B production. The regulation of inhibin B production changes during life. There is an inhibin B peak in serum shortly after birth only partly correlated with an increase in serum FSH, probably reflecting the proliferating activity of the Sertoli cells during this phase of life. Afterwards, inhibin B levels decrease and remain low until puberty, when they rise again, first as a consequence of FSH stimulation and then as a result of the combined regulation by FSH and the ongoing spermatogenesis. In the adult, serum inhibin B shows a clear diurnal variation closely related to that of testosterone. The administration of FSH increases the secretion of inhibin B in normal men, but is much more pronounced in males with secondary hypogonadism. The treatment of infertile men with FSH, however, does not result in an unequivocal inhibin B increase. There is a clear inverse relationship between serum inhibin B and FSH in the adult. Serum inhibin B levels are strongly positively correlated with testicular volume and sperm counts. In infertile patients, inhibin B decreases and FSH increases. In general, there is very good correlation with the degree of spermatogenetic damage, with the arrest at the earlier stages having the lowest inhibin B levels. However, for unknown reasons, there are cases of Sertoli-cell-only syndrome with normal inhibin B levels. Inhibin B and FSH together are a more sensitive and specific marker for spermatogenesis than either one alone. However, the inhibin B concentrations are not a reliable predictor of the presence of sperm in biopsy samples for testicular sperm extraction. Suppression of spermatogenesis with testosterone and gestagens leads to a partial reduction of inhibin B in serum but it is never completely suppressed. In contrast, testicular irradiation in monkeys or humans leads to a rapid and dramatic decrease of inhibin B, which becomes undetectable when germ cells are completely absent. In summary, although inhibin B is a valuable index of spermatogenesis, the measurement of serum inhibin B levels is still of limited clinical relevance for individual patients.
Sodium/iodide symporter (NIS) and pendrin are expressed differently in hot and cold nodules of thyroid toxic multinodular goiter
Authors: Russo D , Bulotta S , Bruno R , Arturi F , Giannasio P , Derwahl M , Bidart JM , Schlumberger M , Filetti S
Published: January 2005

OBJECTIVE: The expression of two iodide transporters, the sodium/iodide symporter (NIS) and pendrin, was analyzed in thyroid tissues of patients with toxic multinodular goiter (TMNG) and non-toxic multinodular goiter (MNG). METHODS: The levels of NIS and pendrin proteins were analyzed in total protein extracts from nodular and non-nodular tissues by Western blot. RESULTS: In tissue samples from TMNG, we found an increased expression of NIS (2.5-fold) in the hot nodules, and similar levels between cold nodules and non-nodular tissues. In contrast, the levels of pendrin were slightly increased in both hot and cold nodules from TMNG, and decreased (about twofold) in cold nodules from MNG. We also noticed that there was no relationship between NIS and pendrin expression. CONCLUSIONS: Our data demonstrate that hot nodules from TMNG express a higher number of iodide transporters (mainly NIS), whereas cold nodules from TMNG, but not from MNG, show levels of the two proteins comparable with normal tissue, suggesting a role in vivo of TSH in maintaining the expression of NIS and pendrin protein in normal thyroid tissue. Finally, different mechanisms are involved in the regulation of NIS and pendrin expression.
RET protein expression has no prognostic impact on the long-term outcome of papillary thyroid carcinoma
Authors: Basolo F , Molinaro E , Agate L , Pinchera A , Pollina L , Chiappetta G , Monaco C , Santoro M , Fusco A , Miccoli P , Elisei R , Capezzone M , Pacini F
Published: January 2005

BACKGROUND: RET proto-oncogene rearrangements (RET/PTC) are causative events in the pathogenesis of a subset of papillary thyroid cancer (PTC). The prevalence of RET/PTC varies in different countries and according to specific clinical features: it is higher after radiation exposure and it is claimed to be higher in young patients. Conflicting results are reported regarding the prognostic role of RET/PTC activation. OBJECTIVE: To investigate the prognostic meaning of RET/PTC rearrangement on the long term outcome of PTC. METHODS: We have studied the expression of the RET encoded protein in 127 papillary thyroid carcinomas by immunohistochemistry using a polyclonal antibody against the tyrosine-kinase domain of the RET protein. These cases have been collected during 1970-1985, and have a mean (+/-S.D.) period of follow-up of 18.6+/-3.7 years (range 12-27 years). The results have been compared with the patients' outcome. RESULTS: The tyrosine-kinase domain of RET was expressed in 82 (64.6%) papillary carcinomas. Among them, RET was highly expressed in 65 (51.2%) cases and moderately expressed in 17 (13.4%). RET expression was absent in 45 (35.4%) cases. No correlation was found between RET expression and other parameters such as sex, age at diagnosis, tumor class and histological variant. Follow-up analysis showed no influence of RET expression on patients' outcome. By multivariate analysis, age (>45 years) and tumor class IV, but not sex and RET expression were adverse prognostic indicators of death. CONCLUSION: In conclusion, our analysis indicates that RET expression is frequently found in PTC, and has no influence on tumor outcome.
Molecular cloning of a functional promoter of the human plakoglobin gene
Authors: Potter E , Braun S , Lehmann U , Brabant G
Published: January 2005

OBJECTIVE: Plakoglobin (Pg) is the only cytoplasmic protein component common to both junctional complexes mediating cell-cell adhesion, adherens junctions and desmosomes. In these complexes Pg appears to act as a linker protein anchoring transmembrane proteins of the cadherin superfamily to the actin cytoskeleton and intermediate filament system respectively. Intercellular adhesion is frequently disturbed in skin diseases and in carcinomas, enabling tumour progression and metastasis. Whereas Pg expression is lost in some thyroid tumours and carcinoma cell lines, little information on Pg gene regulation is currently available owing to a lack of promoter studies. DESIGN AND METHODS: We have cloned and sequenced genomic DNA from a human library that resulted in 979 bp upstream of the published Pg cDNA. The transcriptional start was mapped by rapid amplification of cDNA ends. Methylation-specific PCR of bisulfite-modified cell line DNA was applied to probe the methylation status of a promoter-associated CpG island. Reporter-gene constructs of various promoter fragments were transiently transfected in thyroid carcinoma cell lines and their activities were determined by luciferase measurements. RESULTS AND CONCLUSIONS: A 1 kb DNA fragment harbouring a functional promoter of the human Pg gene was cloned and characterized. The sequence lacks a canonical TATA box, but contains putative CCAAT boxes as well as various putative binding sites for transcription factors, among them SP1 and AP2, proximal to the transcriptional start. Considerable promoter activity was found in thyroid cell lines and deletion analysis indicated that a 300 bp region proximal to the 5'-untranslated region of the mRNA represents the minimal promoter of the human Pg gene. As cells lacking endogenous Pg expression were found to contain methylated CpG dinucleotides in a CpG island located around the transcriptional start site, it is suggested that epigenetic mechanisms such as DNA methylation contribute to dysregulated Pg expression.
Protein kinase C-independent stimulation of activator protein-1 and c-Jun N-terminal kinase activity in human endometrial cancer cells by the LHRH agonist triptorelin
Authors: Grundker C , Schlotawa L , Viereck V , Emons G
Published: January 2005

OBJECTIVE: The expression of luteinizing hormone-releasing hormone (LHRH) and its receptor as a part of an autocrine regulatory system of cell proliferation has been demonstrated in a number of human malignant tumours, including cancers of the endometrium. The signalling pathway through which LHRH acts in endometrial cancer is distinct from that in pituitary gonadotrophs. The LHRH receptor interacts with the mitogenic signal transduction of growth factor receptors via activation of a phosphotyrosine phosphatase, resulting in down-regulation of cancer cell proliferation. In addition, LHRH activates nucleus factor kappaB (NFkappaB) and protects the cancer cells from apoptosis. This study was conducted to investigate additional signalling mechanisms of the LHRH receptor cooperating with NFkappaB in endometrial cancer cells. DESIGN: The LHRH agonist triptorelin-induced activator protein-1 (AP-1) activation was analysed using a pAP-1-SEAP reporter gene assay. Expression of c-jun mRNA was quantified using quantitative reverse transcription (RT)-PCR. c-Jun N-terminal kinase (JNK) activity was measured by quantification of phosphorylated c-Jun protein. RESULTS: Treatment of Ishikawa and Hec-1A human endometrial cancer cells with 100 nM triptorelin resulted in a 3.1-fold and 3.5-fold activation of AP-1 respectively (P<0.05). If the cells had been made quiescent, treatment with triptorelin (100 nM) resulted in a 41.7-fold and 48.6-fold increase of AP-1 activation respectively (P<0.001). This effect was completely blocked by simultaneous treatment with pertussis toxin (PTX). A 17.6-fold and 17.3-fold increase of c-jun mRNA expression respectively (P<0.001) was obtained after 20 min of stimulation with triptorelin (100 nM). Treatment with 1 nM triptorelin resulted in a 12.5-fold or an 11.9-fold increase, and treatment with 10 pM triptorelin resulted in a 6.5-fold or a 5.2-fold increase of maximal c-jun mRNA expression respectively (P<0.001). Maximal c-Jun phosphorylation (68.5-fold and 60.2-fold, respectively, P<0.001) was obtained after 90 min incubation with triptorelin (100 nM). CONCLUSIONS: These results suggest that the LHRH agonist triptorelin stimulates the activity of AP-1 in human endometrial cancer cells mediated through PTX-sensitive G-protein alphai. In addition, triptorelin activates JNK, known to activate AP-1. In earlier investigations we have shown that triptorelin does not activate phospholipase and protein kinase C (PKC) in endometrial cancer cells. In addition, it has been demonstrated that triptorelin inhibits growth factor-induced mitogen activated protein kinase (MAPK, ERK) activity. Thus triptorelin-induced activation of the JNK/AP-1 pathway in endometrial cancer cells is independent of the known AP-1 activators, PKC or MAPK (ERK).
In vitro effect of leptin on LH release by anterior pituitary glands from female rats at the time of spontaneous and steroid-induced LH surge
Authors: De Biasi SN , Apfelbaum LI , Apfelbaum ME
Published: January 2005

OBJECTIVE: The purpose of this work was to study the direct effect of leptin on LH release by anterior pituitary glands from female rats at the time of spontaneous and steroid-induced LH surge. METHODS: LH responsiveness to leptin by pituitaries from rats killed in the afternoon (1500 h) at different stages of the 4-day estrous cycle (diestrus-1: D1; diestrus-2: D2; proestrus; estrus), ovariectomized (OVX; 15 days post-castration) and ovariectomized steroid-primed (OVX-E(2)/Pg; pretreated with 5 microg estradiol and 1 mg progesterone), was evaluated in vitro. Hemi-adenohypophyses were incubated in the presence of synthetic murine leptin for 3 h. RESULTS: Addition of increasing concentrations of leptin (0.1-100 nmol/l) to the incubation medium of proestrus pituitaries produced a dose-related stimulation of LH release; the maximal increase to 315% of control was obtained with 10 nmol/l leptin. Leptin (10 nmol/l) enhanced LH release at all days of the estrous cycle, the greatest response occurring in proestrus (318%) and the lowest at D1 (123%). In order to evaluate the role of nitric oxide (NO) in the action of leptin on LH release, glands from proestrus rats were incubated in the presence of 10 nmol/l leptin with or without 0.3 mmol/l N(G)-monomethyl-l-arginine (NMMA), a competitive inhibitor of NO synthase (NOS). NMMA completely suppressed the stimulation of LH release induced by leptin. Leptin also stimulated LH release by pituitaries from OVX rats, and treatment with steroid hormones led to a marked increase in the response (OVX: 162% compared with OVX-E(2)/Pg: 263%; P<0.05). For comparative analysis, a similar experimental procedure was carried out using GnRH (10 nmol/l). Leptin acts at the pituitary level in a similar manner as GnRH, although with significantly lower potency. CONCLUSIONS: These results confirm and extend previous reports regarding a direct action of leptin at the pituitary level, stimulating LH release by anterior pituitaries from female rats at the time of spontaneous and steroid-induced LH surge. In the female rat pituitary this leptin action is controlled by gonadal steroids and mediated by NO.
Neurosteroid metabolism in the human brain
Authors: Stoffel-Wagner B
Published: January 2005

This review summarizes the current knowledge of the biosynthesis of neurosteroids in the human brain, the enzymes mediating these reactions, their localization and the putative effects of neurosteroids. Molecular biological and biochemical studies have now firmly established the presence of the steroidogenic enzymes cytochrome P450 cholesterol side-chain cleavage (P450SCC), aromatase, 5alpha-reductase, 3alpha-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase in human brain. The functions attributed to specific neurosteroids include modulation of gamma-aminobutyric acid A (GABAA), N-methyl-d-aspartate (NMDA), nicotinic, muscarinic, serotonin (5-HT3), kainate, glycine and sigma receptors, neuroprotection and induction of neurite outgrowth, dendritic spines and synaptogenesis. The first clinical investigations in humans produced evidence for an involvement of neuroactive steroids in conditions such as fatigue during pregnancy, premenstrual syndrome, post partum depression, catamenial epilepsy, depressive disorders and dementia disorders. Better knowledge of the biochemical pathways of neurosteroidogenesis and their actions on the brain seems to open new perspectives in the understanding of the physiology of the human brain as well as in the pharmacological treatment of its disturbances.
Cardiovascular haemodynamics and cardiac autonomic control in patients with subclinical and overt hyperthyroidism
Authors: Petretta M , Bonaduce D , Spinelli L , Vicario ML , Nuzzo V , Marciano F , Camuso P , De Sanctis V , Lupoli G
Published: January 2005

OBJECTIVE: To characterize cardiac structure and function and cardiac autonomic control in patients with subclinical and overt hyperthyroidism. DESIGN: Thirty patients with subclinical hyperthyroidism and 30 with overt disease were selected from patients never previously treated for endocrinological disease in the outpatient clinic of our institution. Twenty normal individuals were studied as control group. METHODS: Left ventricular structure and function and cardiac autonomic control were evaluated, respectively, by two-dimensional Doppler echocardiography and by 24-h Holter recording with heart rate variability analysis. RESULTS: Patients with overt hyperthyroidism showed greater values of left ventricular end-diastolic volume (P<0.05) and left ventricular mass (P<0.05) than patients with subclinical disease. In addition, the mean velocity of left ventricular fibre shortening (P<0.05) and left ventricular ejection fraction (P<0.05) were greater in patients with overt hyperthyroidism than in patients with subclinical disease. No difference in any of these parameters was detectable between normal subjects and patients with subclinical disease. The isovolumic relaxation period was shorter in patients with subclinical hyperthyroidism than in control individuals (P<0.05) and in patients with overt hyperthyroidism (P<0.05). As regards cardiac autonomic control, all time and frequency domain measures decreased progressively from control individuals to patients with subclinical hyperthyroidism and those with overt disease (P<0.001). CONCLUSIONS: Thyrotoxic patients show changes in left ventricular structure and increased echocardiographic indexes of myocardial contractility, whereas the only echocardiographic feature detectable in patients with subclinical hyperthyroidism is an increased velocity of left ventricular relaxation. Cardiac parasympathetic withdrawal is evident in patients with overt hyperthyroidism and in patients with subclinical disease.
Phenotypes associated with replacement of His by Arg in the Pendred syndrome gene
Authors: Sato E , Nakashima T , Miura Y , Furuhashi A , Nakayama A , Mori N , Murakami H , Naganawa S , Tadokoro M
Published: January 2005

BACKGROUND: Pendred syndrome is often associated with inner ear malformations, especially enlarged vestibular aqueduct (EVA). Recently, mutations in the Pendred syndrome gene (PDS) have been reported in patients with EVA, in addition to those with classical Pendred syndrome. OBJECTIVE: The aim of this study was to investigate the genotype-phenotype correlations of PDS. METHODS: Each of the 21 exons and flanking splice regions of PDS was analysed by direct DNA sequencing in nine patients with EVA; allele-specific amplification was performed to confirm the mutation. Genetic analyses were compared with thyroid function tests, perchlorate discharge tests, thyroid volume and pure-tone audiogram. Magnetic resonance imaging was used to determine the volume of the endolymphatic duct and sac of each patient. RESULTS: A missense mutation, H723R, was identified in the homozygous state in three patients and in the heterozygous state in another three. Although none of the patients had goitre, increased serum thyroglobulin and an abnormal degree of iodide release were correlated with the number of mutant alleles identified. However, there was no relationship between the degree of hearing loss and the number of mutant alleles. CONCLUSION: The present study reveals that the number of mutant alleles correlates with the degree of subclinical thyroid abnormality, but not with the degree of hearing loss in Japanese patients with the PDS missense mutation H723R.
Failure of radiotherapy in acromegaly
Authors: Cozzi R , Barausse M , Asnaghi D , Dallabonzana D , Lodrini S , Attanasio R
Published: January 2005

BACKGROUND: Recent data has raised skepticism regarding the long-term effectiveness of radiotherapy (RxT) in acromegaly and its role as an ancillary tool to neurosurgery (Tx). PATIENTS: We evaluated 72 acromegalic patients previously submitted to RxT. Data were discarded in 23 patients, who were lost to follow-up, operated on after RxT or irradiated with techniques different from external conventional fractionated RxT. Among the remaining 49 (five with mixed GH-prolactin adenoma), 34 were irradiated after surgical failure and 15 as primary treatment. A second cycle of RxT was administered in two. RESULTS: (i) GH/IGF-I. After a median follow-up of 14 years (range 3-41), normal age-matched IGF-I levels were reached in eight patients (16%) after 10 years, and GH levels <2.5 microg/l in six (12%) after 9 years. The rate of persistently pathological hormonal levels was still 90% at 25 years. All patients with GH/IGF-I normalization had undergone irradiation without any antisecretory drug. Neither basal GH nor tumor size affected the outcome of RxT. In three patients (6%) a relapse/worsening occurred. (ii) Tumor size. Tumor shrank after 8.5 years in 24 patients (49%), in nine of whom during GH-suppressive treatment. Tumor shrinkage was not predictive of hormonal normalization. (iii) Side-effects. Hypopituitarism was diagnosed in four patients (selective in three and global in one) and GH deficiency in one. Three patients had neurological side-effects and meningioma was shown in two patients. CONCLUSION: RxT is unable to cure acromegaly, because it seldom achieves hormonal normalization even after a very prolonged follow-up. Concomitant antisecretory treatment seems to counteract its effects. RxT can still play a role in those patients with large tumor remnants, because of its capacity to shrink tumor size.
Increased leptin and tumour necrosis factor alpha per unit fat mass in hypopituitary women without growth hormone treatment
Authors: Bulow B , Ahren B , Erfurth EM
Published: January 2005

BACKGROUND: The adipocyte products, leptin and tumour necrosis factor (TNF)alpha, are associated with atherosclerotic diseases and may be factors contributing to the enhanced cardiovascular risk in hypopituitary patients with growth hormone (GH) deficiency. OBJECTIVE: To investigate whether leptin and TNFalpha are increased in a group of hypopituitary women previously found to have increased cardiovascular morbidity, and to compare them with matched individuals of the same sex and age and with similar body composition. DESIGN AND PATIENTS: Thirty-three GH-deficient women with a median age of 64 years (range 39-77 years) were investigated cross-sectionally. The patients were compared with 33 controls matched for sex, age, smoking habits, educational level and residence. METHODS: Body composition was measured by bioimpedance analysis. Fasting concentrations of leptin, TNFalpha and insulin were analysed in patients and controls. RESULTS: There was no significant difference in body mass index or fat mass between patients and controls (both P > or =0.4). Serum leptin did not differ significantly between patients and controls. However, when serum leptin concentrations were expressed per kilogram fat mass, the patients had significantly greater concentrations (P=0.01). Serum TNFalpha and TNFalpha per kilogram fat mass were also significantly greater in the patients (both P=0.001). In contrast, serum insulin did not differ significantly between patients and controls. In the patients, serum leptin concentrations correlated positively with kilogram fat mass (r=0.54, P=0.002). Leptin concentration per kilogram fat mass was positively correlated with insulin (r=0.40, P=0.03). CONCLUSIONS: In contrast to serum concentrations of TNFalpha, serum leptin did not differ from that in controls, implying that leptin is not a major contributor to the previously found increase in cardiovascular morbidity in the hypopituitary women investigated. However, the patients had increased leptin concentrations per unit fat mass, indicating an altered adipocyte secretory function in this group.
Scintigraphic patterns of adrenocortical carcinoma: morpho-functional correlates
Authors: Barzon L , Zucchetta P , Boscaro M , Marzola MC , Bui F , Fallo F
Published: January 2005

OBJECTIVE: Adrenocortical scintigraphy has demonstrated clinical utility in the morpho-functional characterization of adrenal tumors. The aim of this study was to identify possible relationships between the scintigraphic pattern and endocrine and/or morphological data in a series of adrenocortical carcinomas. DESIGN AND METHODS: Twenty-one patients with adrenocortical carcinoma (11 nonfunctioning and 10 hormone-secreting) were investigated with 75Se-methyl-nor-cholesterol scintigraphy. Clinical, hormonal, radiological, and pathological data were analyzed. RESULTS: The adrenal mass showed no radiocholesterol uptake in 18 cases (11 nonfunctioning and 7 functioning lesions). Contralateral normal adrenal gland was visualized in all patients with nonfunctioning tumors, whereas classic bilateral nonvisualization was observed in the 7 cases with hyperfunctioning masses. Three patients with cortisol-producing carcinomas showed radiotracer uptake by the mass, without visualization of the contralateral gland. At histology, the tumors were shown to be undifferentiated adrenocortical carcinomas; they had an aggressive clinical behavior. CONCLUSIONS: Radiocholesterol scintigraphy has an important role in diagnosing adrenocortical carcinomas, which typically are not visualized. However, 30% of hypersecreting adrenocortical carcinomas show an atypical increased tracer uptake, not predictive of the biochemical and histological features of the tumor.
Age-related differences in features associated with polycystic ovary syndrome in normogonadotrophic oligo-amenorrhoeic infertile women of reproductive years
Authors: Bili H , Laven J , Imani B , Eijkemans MJ , Fauser BC
Published: January 2005

OBJECTIVE: To assess the effect of age on clinical, endocrine and sonographic features associated with polycystic ovary syndrome (PCOS) in normogonadotrophic anovulatory infertile women of reproductive years. DESIGN: Cross-sectional study. METHODS: Four hundred and seventy-two oligo-amenorrhoeic infertile patients, presenting with normal FSH and oestradiol concentrations, aged 17-42 years underwent a standardised initial evaluation including: cycle history, body mass index, waist-to-hip ratio and transvaginal ultrasound scanning of ovaries. Fasting blood samples were obtained for extensive endocrine evaluation. Cycle duration, serum levels of gonadotrophins, androgens, oestradiol, insulin, glucose, inhibin B as well as mean number of follicles, ovarian volume and ovarian stroma echogenicity were assessed. RESULTS: Older women had significantly lower LH and androgen and inhibin B serum levels. Similarly, older women presented with a reduced number of ovarian follicles. Age was inversely correlated with cycle duration (r=-0.112, P=0.02), LH (r=-0.154, P=0.001), testosterone (r=-0.194, P=0.001), androstenedione (r=-0.170, P=0.001), dehydroepiandrosterone (r=-0.157, P=0.001), insulin (r=-0.126, P=0.02), inhibin B (r=-0.118, P=0.03) serum levels and mean follicle number (r=-0.100, P=0.03). A positive correlation was observed between age and glucose to insulin ratio (r=0.138, P=0.009). CONCLUSIONS: Advanced age in normogonadotrophic anovulatory infertile women is associated with lower LH and androgen levels and with a decreased number of ovarian follicles. Although during reproductive years observed differences are relatively small, these age-related changes may affect the observed incidence of PCOS.
Is the process of beta-cell destruction in type 1 diabetes at time of diagnosis more extensive in females than in males?
Authors: Pozzilli P , Mesturino CA , Crino A , Gross TM , Jeng LM , Visalli N
Published: January 2005

OBJECTIVE: To evaluate sex differences in patients with insulin-dependent diabetes mellitus (type 1 diabetes) by comparing the integrated parameters of metabolic control at the time of clinical diagnosis and 3 months after intensive insulin therapy in pre-pubertal, pubertal and post-pubertal patients. DESIGN: A total of 331 consecutive patients with newly diagnosed type 1 diabetes were studied. The mean age of the group was 15 years (s.d. 8.1; range 5-23 years). Patients were stratified into three groups according to their age at disease onset: pre-pubertal (ages 5-9 years), pubertal (ages 10-18 years) and post-pubertal (ages 19-23 years). METHODS: Glycated haemoglobin (HbA(1c)), insulin dose and both basal and glucagon-stimulated C-peptide were evaluated at diagnosis and after 3 months of insulin therapy. RESULTS: We found that females diagnosed after puberty were those with the lowest basal C-peptide compared with males (P=0.005). No statistically significant differences were observed for other metabolic parameters. When the entire group was evaluated, females at the time of diagnosis showed significant lower body mass index (P=0.001), lower basal C-peptide (P=0.021) and higher HbA(1c) (P=0.023) and required more insulin than males (P<0.001). After 3 months of therapy, only a significantly greater dose of insulin was observed in females compared with males (P=0.001), with similar good metabolic control as assessed by HbA(1c). CONCLUSIONS: We conclude that the process of beta-cell destruction at diagnosis may be more extensive in post-pubertal females than in males. Moreover, after the introduction of insulin therapy, females and males show similar metabolic parameters, although females still require significantly more insulin than males to achieve good metabolic control, 3 months after diagnosis.
The expression and regulation of Bcl-2-related ovarian killer (Bok) mRNA in the developing and adult rat testis
Authors: Suominen JS , Yan W , Toppari J , Kaipia A
Published: January 2005

OBJECTIVE: To study the role of Bcl-2-related ovarian killer (Bok) in the regulation of apoptosis in the testis of developing and adult rat. METHODS: Bok mRNA expression was analyzed by Northern hybridization before and after culturing rat seminiferous tubules in vitro. Seminiferous tubules were cultured with different hormones and growth factors. Changes in the expression level of Bok mRNA during testicular development was analyzed by Northern hybridization. Localization of Bok mRNA was verified by in situ hybridization. RESULTS: Bok mRNA was highly expressed in the rat testis, varying during development. Highest expression levels were found in immature rats. Highest hybridization intensity appeared to be in spermatogonia, pachytene spermatocytes and Sertoli cells. Treatment with FSH was able to inhibit spontaneous increase of Bok mRNA expression that occurred in the defined stages of the rat seminiferous epithelium. CONCLUSIONS: FSH protects germ cells from apoptosis and this protective effect may at least partly be due to the inhibition of Bok gene expression. The amount of apoptosis varies during testicular development and highest expression of Bok mRNA occurs at the time of apoptosis, suggesting a possible role for Bok in its regulation.
Gonadal malignant germ cell tumors express immunoreactive inhibin/activin subunits
Authors: Cobellis L , Cataldi P , Reis FM , De Palo G , Raspagliesi F , Pilotti S , Arcuri F , Petraglia F
Published: January 2005

OBJECTIVE: Inhibin and activin are proteins produced by ovarian granulosa cells and testicular Sertoli cells and are members of the transforming growth factor-beta superfamily. Since increased circulating levels of immunoreactive inhibin were detected in women with malignant ovarian tumors, they were proposed as tumor markers for ovarian carcinoma. Immunohistochemical studies later confirmed the presence of inhibin and activin subunits in granulosa cell tumors and epithelial ovarian cancer, as well as in Sertoli and Leydig cell testicular cancer. However, there is discrepant information on the detection of inhibin and activin in malignant germ cell tumors (MGCT). The aim of the present study was to evaluate the immunohistochemical expression of the inhibin/activin alpha, betaA and betaB subunits in ovarian and testicular MGCT specimens using polyclonal antisera. METHODS: The ovarian tissue samples were composed of 19 MGCT, including dysgerminoma (n=18) and yolk sac tumor (n=1). The testis specimens included classic seminomas (n=20), embryonal carcinomas (n=7), choriocarcinomas (n=2), and yolk sac tumor (n=1). RESULTS: Ovarian and testicular malignant germ cell tumors expressed positive staining for inhibin/activin alpha, betaA and betaB subunits, with some variations between and within individual tumors: while ovarian dysgerminomas were diffusely positive for alpha, betaA and betaB, testicular tumors expressed alpha and betaB subunits, whereas betaA staining was weak. CONCLUSIONS: The present results show positive staining for inhibin/activin subunits in ovarian and testicular MGCT, suggesting a possible role in tumorigenesis with the resultant clinical implication.
Impairment of insulin-stimulated GLUT4 translocation in skeletal muscle and adipose tissue in the Tsumura Suzuki obese diabetic mouse: a new genetic animal model of type 2 diabetes
Authors: Miura T , Suzuki W , Ishihara E , Arai I , Ishida H , Seino Y , Tanigawa K
Published: January 2005

BACKGROUND: In skeletal muscle and adipocytes, insulin-stimulated glucose transport has been known to occur through the translocation of glucose transporter (GLUT) 4 from the intracellular pool to the plasma membrane. The Tsumura Suzuki obese diabetic (TSOD) mouse, a new genetic animal model of type 2 diabetes, develops moderate degrees of obesity and diabetes that are especially apparent in animals more than 11 weeks old. A defect in insulin stimulation of GLUT4 translocation also contributes to the characteristics of type 2 diabetes. OBJECTIVE: To characterize this mouse further, we examined the alteration in insulin-stimulated GLUT4 translocation in the skeletal muscle and adipose tissue. METHODS: For glucose and insulin tolerance tests, the mice were given glucose or insulin and blood samples were collected. After isolation of low-density microsomal membrane and plasma membrane from skeletal muscle and adipose tissue, insulin-stimulated translocation of GLUT4 in these TSOD mice was examined by Western blot. RESULTS AND CONCLUSIONS: TSOD mice showed a significant increase in blood glucose after the glucose load, and exhibited a significantly attenuated decrease in blood glucose concentrations after administration of insulin, compared with that in control Tsumura Suzuki non-obese (TSNO) mice. The insulin-stimulated translocation of GLUT4 from low-density microsomal membranes to plasma membrane was significantly reduced in both skeletal muscle and adipose tissue of TSOD mice. These results indicate that the reduced insulin sensitivity in diabetic TSOD mice is presumably due, at least in part, to the impaired GLUT4 translocation by insulin in both skeletal muscle and adipocytes.
Metabolic effects of 20 kDa and 22 kDa human growth hormones on adult male spontaneous dwarf rats
Authors: Ishikawa M , Hiroi N , Kamioka T , Tanaka T , Tachibana T , Ishikawa H , Miyachi Y
Published: January 2005

BACKGROUND: Two molecular forms of human GH (hGH) have been shown to be biologically active. The 20 kDa form has been reported to have weaker diabetogenic and lipolytic actions than the 22 kDa form. OBJECTIVE: To analyze the carbohydrate metabolism of 20 kDa and 22 kDa hGH, using the adult male spontaneous dwarf rat (SDR), which is GH deficient. DESIGN: SDRs were given 20 kDa or 22 kDa hGH in doses of 125 microg/rat or 500 microg/rat, or saline, for 10 days, and their weight, serum IGF-I, glucose, insulin, leptin and body composition were measured. RESULTS: Weight and serum IGF-I increased both in the 20 kDa and 22 kDa groups, but IGF-I concentrations were significantly lower in the 20 kDa group than in the 22 kDa group. Serum glucose was not increased by either 20 kDa or 22 kDa hGH, whereas insulin was significantly increased after the higher dose of the 22 kDa hGH. Although blood concentrations of leptin were decreased by both 20 kDa and 22 kDa hGH, values were lower in the high-dose 20 kDa group than in the group given the same dose of 22 kDa hGH. Both forms of GH increased the percentage body water and body protein content, and decreased the percentage of body fat by the same degree. The observation that the higher dose of the 22 kDa hGH increased insulin concentrations without changing blood glucose demonstrates that this concentration of the hormone induces insulin resistance, whereas the same dose of 20 kDa hGH does not. CONCLUSIONS: The results can be interpreted to indicate that the higher dose of the 22 kDa hGH has diabetogenic activity, as reported previously, whereas the 20 kDa hGH has lower diabetogenic activity. The 20 kDa form of hGH may therefore be more useful in treating adult GH deficiency, especially those with severe obesity.
Dexamethasone-induced insulin resistance and pancreatic adaptive response in aging rats are not modified by oral vanadyl sulfate treatment
Authors: Barbera M , Fierabracci V , Novelli M , Bombara M , Masiello P , Bergamini E , De Tata V
Published: January 2005

OBJECTIVE: To explore the adaptive response of the endocrine pancreas in vivo and in vitro and the possible beneficial effect of the insulino-mimetic agent vanadyl sulfate (VOSO(4)), using glucocorticoid treatment to increase insulin resistance, in aging rats. DESIGN AND METHODS: Dexamethasone (Dex) (0.13 mg/kg b.w.) was administered daily for 13 days to 3- and 18-month old Sprague-Dawley rats and oral VOSO(4) was given from the 5th day. Plasma glucose, insulin and free fatty acids (FFA) concentrations were measured during these treatments and the insulin secretory response of the isolated perfused pancreas was assessed at the end of the experiment. RESULTS AND CONCLUSIONS: In both young and aging rats, particularly in the latter, hyperinsulinemia and increased in vitro insulin responsiveness to glucose were observed in response to Dex treatment, concomitant with an increase in plasma FFA concentrations. Thus, in glucocorticoid-treated animals, the beta-cell adaptive response occurred in both age groups and could possibly be mediated by increased circulating FFA; however, it was insufficient to prevent hyperglycemia in 60% of aging animals. Oral VOSO(4) administration failed to correct Dex-induced alterations in glucose and lipid metabolism, although it influenced in vitro beta-cell responsiveness to stimuli in aging rats.
Biology of the gonadotropin-releasing hormone system in gynecological cancers
Authors: Grundker C , Gunthert AR , Westphalen S , Emons G
Published: January 2005

The expression of GnRH and its receptor as a part of an autocrine regulatory system of cell proliferation has been demonstrated in a number of human malignant tumors, including cancers of the breast, ovary and endometrium. Dose-dependent antiproliferative effects of GnRH agonists in cell lines derived from these cancers have been observed by various investigators. GnRH antagonists also have marked antiproliferative activity in most breast, ovarian and endometrial cancer cell lines tested, indicating that the dichotomy of GnRH agonists and antagonists might not apply to the GnRH system in cancer cells. The classical GnRH receptor signal-transduction mechanisms, known to operate in the pituitary, are not involved in the mediation of antiproliferative effects of GnRH analogs in cancer cells. Rather, the GnRH receptor interacts with the mitogenic signal transduction of growth factor receptors and related oncogene products associated with tyrosine kinase activity, via activation of a phosphotyrosine phosphatase, resulting in downregulation of cancer cell proliferation. In addition, GnRH activates nuclear factor kappaB and protects the cancer cells from apoptosis. Furthermore, GnRH induces activation of the c-Jun N-terminal kinase/activator protein-1 (AP-1) pathway independent of the known AP-1 activators, protein kinase or mitogen activated protein kinase.