bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor gamma-2 gene on adiposity, insulin sensitivity and lipid profile in the Spanish population
Authors: Gonzalez Sanchez JL , Serrano Rios M , Fernandez Perez C , Laakso M , Martinez Larrad MT
Published: January 2005

OBJECTIVE: To investigate the role of the Pro12Ala peroxisome proliferator-activated receptor (PPAR) gamma-2 polymorphism in the susceptibility to the insulin resistance syndrome and its metabolic complications in a population-based nationwide multicenter study in Spain. DESIGN: 464 unrelated adults (45.3% men and 54.7% women) aged between 35 and 64 years were randomly chosen from a nationwide population-based survey of obesity and related conditions including insulin resistance and cardiovascular risk factors. METHODS: Anthropometric determinations included: body mass index (BMI), waist-to-hip ratio, sagittal abdominal diameter; biochemical determinations included: fasting plasma glucose concentration and concentration 2 h after an oral glucose tolerance test (OGTT), total cholesterol, high and low density lipoprotein-cholesterol, triglycerides, leptin and insulin. Systolic and diastolic blood pressure were also measured. Genotyping of the PPARgamma-2 Pro12Ala polymorphism was determined by polymerase chain reaction and single strand conformation polymorphism analysis. RESULTS: The Ala12 allele frequency was higher in obese men than in lean men (0.15 vs 0.08, P=0.03). Men carriers of the Ala12 allele had a higher BMI than non-carriers (38.9% vs 21.3%; adjusted odds ratio 2.36, 95% confidence interval 1.10-5.05, P=0.03). However, despite higher BMI obese men carriers of the Ala12 allele had lower sagittal abdominal diameter than Pro12 homozygotes (24.1+/-3.2 vs 26.3+/-2.5 cm, P=0.01). The Ala12 allele was associated with lower total triglycerides levels in the overall population and it was also associated with lower fasting insulin levels and a higher insulin sensitivity by homeostasis model assessment (HOMA) in women. CONCLUSIONS: Our results suggest that the Pro12Ala polymorphism of the PPARgamma-2 gene promotes peripheral deposition of adipose tissue and increased insulin sensitivity for a given BMI. The results in women might be due to their different adipose tissue distribution.
Negative regulation of adipose-expressed galectin-12 by isoproterenol, tumor necrosis factor alpha, insulin and dexamethasone
Authors: Fasshauer M , Klein J , Lossner U , Paschke R
Published: January 2005

OBJECTIVE: Galectin-12 has recently been shown to be a predominantly adipocyte-expressed protein which is stimulated by insulin-sensitizing thiazolidinediones and possesses apoptosis-inducing activity. METHODS: To further clarify galectin-12 regulation and its potential involvement in the development of insulin resistance, 3T3-L1 adipocytes were chronically treated with various hormones known to impair insulin sensitivity, and galectin-12 mRNA was measured by quantitative real-time reverse transcription-polymerase chain reaction. RESULTS: Treatment of 3T3-L1 cells for 16 h with 10 micromol/l isoproterenol, 100 nmol/l insulin, 0.6 nmol/l tumor necrosis factor alpha (TNFalpha), and 100 nmol/l dexamethasone reduced galectin-12 gene expression between 47% and 85%. These negative effects were dose-dependent with significant inhibition detectable at concentrations as low as 10 nmol/l isoproterenol, 0.06 nmol/l TNFalpha, and 1 nmol/l dexamethasone. Furthermore, the inhibitory effect of isoproterenol could be almost completely reversed by pretreatment with the beta-adrenergic antagonist propranolol and mimicked by stimulation of G(S)-proteins with cholera toxin or by activation of adenylyl cyclase with forskolin and dibutyryl-cAMP. CONCLUSIONS: Our results suggest that galectin-12 is an adipocyte-expressed protein which is downregulated by various insulin resistance-inducing hormones. These findings imply a role for galectin-12 in the pathogenesis of insulin resistance.
Serum GH response to pharmacological stimuli and physical exercise in two siblings with two new inactivating mutations in the GH-releasing hormone receptor gene
Authors: Salvatori R , Fan X , Veldhuis JD , Couch R
Published: January 2005

OBJECTIVE: Inactivating mutations of the GH-releasing hormone receptor (GHRHR) gene (GHRHR) cause familial isolated GH deficiency (IGHD) type IB. The GH response to physical exercise (PE) in patients lacking GHRHR has never been studied. We hypothesized that subjects lacking functional GHRHR may be a model to study GH response to PE. DESIGN: We have analyzed peripheral genomic DNA of a family with two sibs affected by IGHD IB for mutations in the GHRHR, studied the patients' GH response to different GH secretagogues and to PE, and examined the morphology of their pituitary gland by magnetic resonance imaging (MRI). METHODS: The GHRHR was analyzed by direct sequencing of the 13 exons, intron-exon boundaries, and of the proximal 327 bp of the promoter region in the index case. The patients' GH response to GHRH and standardized PE was studied twice, using a GH ultrasensitive assay in the second round of testing. RESULTS: Both subjects were compound heterozygotes for two previously undescribed mutations in the GHRHR that are predicted to cause complete lack of functional GHRHR protein: a nonsense mutation in codon 43 (Q43X), and a splice mutation at the beginning of intron 3 (IVS3+1G-->A). MRI showed hypoplasia of their anterior pituitaries. Both subjects had a small but detectable increase in serum GH after maximal PE. CONCLUSIONS: GHRHR mutations need to be considered in IGHD IB patients even in the absence of parental consanguinity, and patients lacking GHRHR may provide a model to study the mechanism by which PE influences GH secretion.
Idiopathic precocious puberty versus puberty in adopted children; auxological response to gonadotrophin-releasing hormone agonist treatment and final height
Authors: Kempers MJ , Otten BJ
Published: January 2005

OBJECTIVE: The objective of this study was to evaluate the characteristics of puberty and response to gonadotrophin-releasing hormone (GnRH) agonist treatment in adopted children compared with children with idiopathic precocious puberty (IPP). METHODS: We studied 17 girls with central IPP (group A) and 11 girls adopted from Asia and Central and South America (group B) with respect to auxological data at presentation of puberty and response to GnRH agonist treatment. RESULTS: In adopted girls, age at onset of puberty was later and duration of treatment was shorter. At the start of treatment, height-standard deviation score (H-SDS) was +1.67 s.d. in group A. In group B, H-SDS was comparably increased (+0.04 s.d.) assuming that the mean H-SDS in their native country is lower than the mean on the Dutch curve. During treatment, H-SDS decreased in both groups. Group A reached a final height (FH) of 166.2 cm (-0.3 s.d.) and group B of 156.1 cm (-1.9 s.d.). Predicted adult height (PAH) at the start of treatment underestimated FH in group A and overestimated FH in group B. At the end of treatment, PAH overestimated FH in both groups. The SDS for weight was above the mean in both groups at the start of treatment and increased even more during treatment. The age of occurrence of menses after treatment was stopped was the same in both groups (12.7 and 12.8 Years respectively). CONCLUSION: Despite the difference in timing of puberty between girls with IPP and adopted girls with early puberty, their response to treatment was similar in many aspects.
Vitamin D receptor genotype is associated with Addison's disease
Authors: Pani MA , Seissler J , Usadel KH , Badenhoop K
Published: January 2005

OBJECTIVE: Autoimmune Addison's disease is a rare disorder which results from the T cell-mediated destruction of adrenocortical cells. A number of genetic susceptibility markers are shared by Addison's disease, type 1 diabetes, Graves' disease and Hashimoto's thyroiditis. The vitamin D endocrine system has been shown to influence immune regulation. Variants of the nuclear vitamin D receptor (VDR) gene were found to be associated with type 1 diabetes and thyroid autoimmunity amongst others. We therefore investigated the role of VDR polymorphisms in Addison's disease. DESIGN AND METHODS: Patients (n=95) and controls (n=220) were genotyped for VDR polymorphisms FokI, BsmI, ApaI and TaqI. RESULTS: The 'ff' (13.7% vs 5.5%; P=0.0243; odds ratio = 2.75) and the 'tt' (28.4% vs 14.1%; P=0.0043; odds ratio = 2.42) genotypes were significantly more frequent in patients than in controls. Furthermore, the BsmI genotype distribution differed significantly between patients and controls (chi(2)=6.5016 (2 d.f.) P=0.0387). CONCLUSIONS: These data suggest that the VDR genotype is associated with Addison's disease. The mechanisms by which distinct receptor variants might confer disease susceptibility remain to be elucidated.
The risk of myocardial infarction is enhanced by a synergistic interaction between serum insulin and smoking
Authors: Bennet AM , Brismar K , Hallqvist J , Reuterwall C , De Faire U
Published: January 2005

OBJECTIVES: To evaluate the relationship between levels of serum insulin, the homeostasis model assessment (HOMA) and IGF-binding protein-1 (IGFBP-1) as factors related to myocardial infarction (MI) risk, and their interaction with lifestyle-related risk factors. DESIGN: The Stockholm epidemiology programme (SHEEP), a case-control study, consisting of 749 first-time MI cases (510 men, 239 women) and 1101 healthy controls (705 men, 396 women) was used. METHODS: The risk of developing MI was assessed by calculating odds ratios (OR) and synergistic interactions (SI) between serum insulin, IGFBP-1, HOMA and other variables related to MI risk (including smoking) in men and women. RESULTS: Subjects with elevated levels of insulin and HOMA (>75th percentile) had increased MI risks when compared with individuals with low levels. ORs for elevated insulin and HOMA (adjusted for age and residential area) for men: insulin 1.6 (95% confidence interval (CI) 1.3-2.1) and HOMA 1.5 (95% CI 1.1-1.9) and for women: insulin 2.1 (95% CI 1.5-2.9) and HOMA 1.9 (95% CI 1.3-2.8). Women with low levels of IGFBP-1 (<10th percentile) showed a tendency towards elevated MI risk even if this was not statistically significant (OR 1.5 (95% CI 0.9-2.6)). Smokers with high levels of serum insulin had greatly increased MI risk (OR for men: 4.7 (95% CI 3.0-7.2) and OR for women: 8.1 (95% CI 4.5-14.8)). SI scores based upon these interactions were statistically significant. CONCLUSIONS: These results might have preventive cardiovascular implications as they clearly suggest that subjects with insulin resistance are particularly susceptible to the hazards of smoking.
Iodine in drinking water in Denmark is bound in humic substances
Authors: Andersen S , Petersen SB , Laurberg P
Published: January 2005

OBJECTIVE: The iodine intake level is important for the occurrence of thyroid disorders in a population. We have previously found that iodine in drinking water is related to iodine excretion but whether iodine is present as iodide or bound in other molecules remains unknown. DESIGN: We measured iodine in drinking water from 22 locations in Denmark. Six locations were selected by iodine content for further tap water analysis (Skagen 140 micro g/l, Samsoe 56 micro g/l, Nykoebing S. 50 micro g/l, Nakskov 40 micro g/l, Ringsted 38 micro g/l, Copenhagen 19 micro g/l). METHODS: HPLC size exclusion before (Skagen) and after (all sites) freeze drying and measurement of absorbance (280 nm) and iodine in fractions, and fluorescence spectroscopy of bulk organic matter in Skagen drinking water. RESULTS: Iodine content was unaltered after 3 Years (P=0.2). All samples contained organic molecules with characteristics similar to humic substances. Most iodine eluted with humic substances (Skagen 99%, Ringsted 98%, Nykoebing S. 90%, Copenhagen 90%, Samsoe 75%, Nakskov 40%). Changing pH and ionic strength and preincubation with iodide indicated that iodine was bound in humic substances. Humic substances may affect thyroid function but differ with geology. Geological and geochemical data agree with tap water humic substances having been released from marine deposits. Iodine is abundant in the marine environment and marine deposits are particularly rich in iodine. Correlation analysis (r=0.85, P=0.03) conform to iodine in drinking water, suggesting marine humic substances at the source rock. CONCLUSION: Iodine in Danish drinking water varied considerably. In drinking water with a high iodine content, the iodine mainly eluted with humic substances derived from marine source rock. We hypothesize that iodine in drinking water in general suggests coexisting humic substances of marine origin.
Insulin influences the nitric oxide cyclic nucleotide pathway in cultured human smooth muscle cells from corpus cavernosum by rapidly activating a constitutive nitric oxide synthase
Authors: Anfossi G , Massucco P , Mattiello L , Balbo A , Russo I , Doronzo G , Rolle L , Ghigo D , Fontana D , Bosia A , Trovati M
Published: January 2005

AIMS: We have evaluated, in cultured human cavernosal smooth muscle cells, the expression and activity of calcium-dependent constitutive nitric oxide synthase (cNOS) and the ability of insulin to induce nitric oxide (NO) production and to increase intracellular cyclic nucleotides guanosine 3',5'-cyclic monophosphate (cGMP) and adenosine 3',5'-cyclic monophosphate (cAMP). METHODS: cNOS mRNA was detected by RT-PCR amplification, cNOS protein by immunofluorescence, cNOS activity as l-[3H]-citrulline production from l-[3H]-arginine and cyclic nucleotides by radioimmunoassay. RESULTS: cNOS mRNA and cNOS protein were found in cultured cells; cNOS activity was increased by 5-min exposure to 1 micro mol/l calcium ionophore ionomycin (from 0.1094+/-0.0229 to 0.2685+/-0.0560 pmol/min per mg cell protein, P=0.011) and to 2 nmol/l insulin (from 0.1214+/-0.0149 to 0.2045+/-0.0290 pmol/min per mg cell protein, P=0.041). Insulin increased both cGMP and cAMP in a dose- and time-dependent manner (i.e. with 2 nmol/l insulin, cGMP rose from 2.71+/-0.10 to 6.80+/-0.40 pmol/10(6) cells at 30 min, P=0.0001; cAMP from 1.26+/-0.06 to 3.02+/-0.30 pmol/10(6) cells at 60 min, P=0.0001). NOS inhibitor N(G)-monomethyl-l-arginine and phosphatidylinositol 3-kinase (PI 3-kinase) inhibitors wortmannin and LY 294002 blunted these effects of insulin. The action of insulin on cyclic nucleotides persisted in the presence of phosphodiesterase inhibition, guanylate cyclase activation by NO donors and adenylate cyclase activation by Iloprost or forskolin. CONCLUSION: Human cavernosal smooth muscle cells, by expressing cNOS activity, are a source of NO and not only its target; in these cells, insulin rapidly activates cNOS through a PI 3-kinase pathway, with a consequent increase of both cyclic nucleotides, thus directly influencing the mechanisms involved in penile vascular tone and interplaying with classical haemodynamic mediators.
Enhanced serum oestrogen levels and highly steroidogenic, luteinized atretic follicles in the ovaries of the Djungarian hamster (Phodopus sungorus) kept under a short photoperiod from birth
Authors: Van Den Hurk R , Dijkstra G , De Jong FH
Published: January 2005

OBJECTIVE: In contrast to the elaborate information available on the effects of the photoperiod on the testes of hamsters, little is known about the influence on their ovaries. This study aimed to describe the ovarian follicular development and steroid hormone production in Djungarian hamsters kept from birth under a short daylight regime. DESIGN AND METHODS: Female Djungarian hamsters (Phodopus sungorus) were kept under two different light regimes: (i) 16 h light:8 h darkness (long daylight; LD) and (ii) 4 h light:20 h darkness (short daylight; SD). They were killed at 28, 56 and 80 days after birth; blood and ovaries were collected. Ovaries were either fixed in Bouin's solution or frozen. Fixed material was dehydrated, embedded in paraffin, serially sectioned at 5 microm and stained with haematoxylin and eosin, whereafter all healthy and atretic follicles were classified and counted. 3beta-Hydroxysteroid dehydrogenase (3beta-HSD) was histochemically demonstrated in 10 microm sections of frozen ovaries. Serum oestradiol-17beta and progesterone levels were determined by RIA. RESULTS: The numbers of healthy preantral and antral follicles were higher in LD than in SD hamsters. Antral follicles did not significantly differ in number during development in LD hamsters, but they were completely absent from 80-day-old SD animals. In LD animals the number of apoptotic preantral follicles dramatically increased with age. In SD animals the numbers of apoptotic antral follicles strongly decreased with age, whereas numerous non-apoptotic follicles with luteinized granulosa cells and a degenerated oocyte appeared, and in increasing numbers with age. During development, moderate 3beta-HSD activity was present in interstitial cells, theca cells of healthy follicles, and in both theca and granulosa cells of degenerating follicles. Strong enzyme activity was found in the hypertrophied granulosa cells of luteinized atretic follicles. Mean serum progesterone values varied from 2 to 6 nmol/l and were not different in LD and SD hamsters. Mean serum oestradiol levels varied from 132 to 542 and 325 to 2353 pmol/l in LD and SD hamsters respectively. The highest oestradiol levels were found in SD animals at day 28 of development. CONCLUSIONS: Folliculogenesis was dramatically disturbed in Djungarian hamsters raised under a short photoperiod. These animals developed high serum oestradiol levels and numerous luteinized atretic follicles with highly steroidogenic granulosa cells, which appear to be the source of the increased serum oestradiol levels.
Circulating procalcitonin and cleavage products in septicaemia compared with medullary thyroid carcinoma
Authors: Ittner L , Born W , Rau B , Steinbach G , Fischer JA
Published: January 2005

OBJECTIVE: Raised plasma levels of procalcitonin (proCT) represent an early marker for septicaemia. They are related to disease severity and inversely to outcome and response to treatment. ProCT is presumably synthesised in tIssues other than the thyroid C-cells which are the source of calcitonin (CT) in normal physiology. This study compares proCT and its cleavage products in the serum of patients with septicaemia with those in medullary thyroid carcinoma (MTC). METHODS: Immunoreactive proCT and its cleavage products were extracted from the serum of patients with septicaemia or MTC using octadecylsilyl silica columns and characterised by reversed phase HPLC and Western blot analysis. ProCT, CT(1-32) and the flanking peptides PAS-57 and PDN-21 were recognised with antibodies specific for the individual peptides. RESULTS: ProCT and a 10 kDa polypeptide were recognised with antibodies to PAS-57, CT(1-32) and PDN-21. An 8 kDa proCT fragment was detected with antibodies to CT and PDN-21. However, intact CT(1-32), PAS-57 and PDN-21, found in the serum of MTC patients, were undetectable. The results indicate partial cleavage of proCT in septicaemia different from that in MTC patients. CONCLUSIONS: ProCT and 10 and 8 kDa proCT fragments were recognised in the circulation of septic patients. They were different from the known proCT-processing products PAS-57, CT(1-32) and PDN-21 identified in the serum of normal subjects and of MTC patients. Distinct cleavage of proCT may contribute to the symptoms of septicaemia.
Ghrelin-induced GH secretion in normal subjects is partially resistant to homologous desensitization by GH-releasing peptide-6
Authors: Micic D , Macut D , Sumarac-Dumanovic M , Kendereski A , Popovic V , Deghenghi R , Dieguez C , Casanueva FF
Published: January 2005

OBJECTIVE: GH secretagogues and GH-releasing hormone (GHRH) exert a complex cross-talk at the somatotrope cell, and undertake homologous and heterologous desensitization. On the other hand, the discovery of ghrelin as a new factor implicated in the regulation of GH secretion makes a thorough assessment of its properties and cell biology processes mandatory. In order to implement this, three different testing schedules were devised using the administration, on the same day, of two GH stimuli administered in sequential order 120 min apart. The two aims of the study were (a) to evaluate the relative potency of ghrelin in comparison with other GH stimulants and (b) to assess the presence of homologous or heterologous desensitization between these compounds. DESIGN: The different testing days performed in random order were (a) on one day, saline was administered at time 0 min and ghrelin at time 120 min, (b) on another testing day, GHRH was administered at 0 min followed by ghrelin at 120 min and (c) on the last testing day, GH-releasing peptide-6 (GHRP-6) and ghrelin were injected at 0 and 120 min respectively. Ghrelin, GHRH and GHRP-6 were always administered at 1 microg/kg i.v., and plasma GH was measured. PATIENTS: Six normal subjects participated in the study after providing informed consent, and each was assessed on three different testing days, at least 1 week apart. RESULTS: Saline did not modify peak GH (means+/-s.e.) values (1.5+/-0.6 microg/l), and ghrelin administered 120 min later induced a significant GH rise (39.9+/-2.8 microg/l). On a different testing day, GHRH induced a GH peak (9.4+/-2.8 microg/l) lower than that of ghrelin injected 120 min later (26.8+/-4.7 microg/l). On the last testing day, GHRP-6 at time 0 induced a GH peak of 18.4+/-5.9 microg/l and ghrelin 120 min later a peak of 19.8+/-2.9 microg/l. The ghrelin-mediated GH secretion after GHRP-6 was significantly lower than the GH elicited by ghrelin when the preceding administration was saline. This demonstrated that ghrelin was partially affected by GHRP-6 and was not affected by GHRH. CONCLUSIONS: Calculated at equal mass doses or in molecular terms, ghrelin appears to be a more potent stimulus than GHRP-6 and GHRH. Ghrelin was completely insensitive to the previous administration of GHRH as well as relatively resistant to the homologous desensitization exerted by GHRP-6.
Pregnancy-associated and placental proteins in the placental tissue of normal pregnant women and patients with pre-eclampsia at term
Authors: Bersinger NA , Groome N , Muttukrishna S
Published: January 2005

OBJECTIVE: Pre-eclampsia is a placental disease of unknown cause. Maternal circulating concentrations of a number of protein markers are altered (mainly increased) in pre-eclampsia in comparison with controls of matched gestational age. Inhibin A and activin A were found to be elevated even before the onset of the disease. The aim of this study was to compare the levels of inhibin A, activin A: follistatin ratio, leptin, pregnancy-associated plasma protein-A (PAPP-A), human placental lactogen (HPL), placenta growth factor (PLGF) and pregnancy-specific beta1-glycoprotein (SP1) in placental extracts of normal pregnant women and pre-eclampsia patients at term. METHODS: Placental tissue from normal pregnancies (n=14) and patients with pre-eclampsia (n=13) were collected at term (> or =37 weeks of gestation) and stored at -80 degrees C. The frozen tissue pieces were homogenised and the above-mentioned proteins were measured by specific enzyme-linked immunosorbent assays. RESULTS: Placental contents of inhibin A and PAPP-A were significantly higher (P<0.05) in pre-eclampsia placental extracts compared with the controls. Activin A:follistatin ratio was higher (23) in pre-eclampsia extracts than in the controls (15). Leptin, PLGF, SP1 and HPL levels were not altered in the term pre-eclampsia placenta. Inhibin A and PAPP-A contents were increased in the placental extracts of pre-eclampsia patients. CONCLUSION: Our data suggest that the placenta, possibly by a compensatory mechanism, is at least in part responsible for the altered serum levels observed in pre-eclampsia.
Serotonergic involvement in stress-induced vasopressin and oxytocin secretion
Authors: Jorgensen H , Knigge U , Kjaer A , Warberg J
Published: January 2005

OBJECTIVE: To investigate the involvement of serotonin (5-hydroxytryptamine - 5-HT) receptors in mediation of stress-induced arginine vasopressin (AVP) and oxytocin (OT) secretion in male rats. DESIGN: Experiments on laboratory rats with control groups. METHODS: Different stress paradigms were applied after pretreatment with intracerebroventricular infusion of saline or different 5-HT antagonists. RESULTS: Restraint stress (5 min), hypotensive hemorrhage or dehydration for 24 h increased AVP secretion fivefold and OT secretion threefold. Swim stress for 3 min had no effect on AVP secretion, but increased OT secretion threefold. Ether vapor or hypoglycemia had no effect on AVP or OT secretion. The restraint stress-induced AVP response was inhibited by pretreatment with the 5-HT(2A+2C) antagonists ketanserin (KET) and LY-53857 (LY) and the 5-HT(3+4) antagonist ICS-205930 (ICS), whereas the 5-HT(1A) antagonist WAY-100635 (WAY) had no effect. The OT response to restraint stress was inhibited by WAY, KET and LY but not by ICS. KET and LY inhibited OT response to dehydration, and LY inhibited OT response to hemorrhage. Neither of the antagonists affected AVP responses to dehydration or hemorrhage, nor the swim stress-induced OT response. CONCLUSION: 5-HT(2A), 5-HT(2C) and possibly 5-HT(3) and 5-HT(4) receptors, but not 5-HT(1A) receptors, are involved in the restraint stress-induced AVP secretion. 5-HT does not seem to be involved in the dehydration- or hemorrhage-induced AVP response. The restraint stress-induced OT response seems to be mediated via 5-HT(1A), 5-HT(2A) and 5-HT(2C) receptors. The dehydration and hemorrhage-induced OT responses are at least mediated by the 5-HT(2A) and 5-HT(2C) receptors. The 5-HT(3) and 5-HT(4) receptors are not involved in stress-induced OT secretion.
Serum thyroglobulin and 131I whole body scan after recombinant human TSH stimulation in the follow-up of low-risk patients with differentiated thyroid cancer
Authors: Torlontano M , Crocetti U , D'Aloiso L , Bonfitto N , Di Giorgio A , Modoni S , Valle G , Frusciante V , Bisceglia M , Filetti S , Schlumberger M , Trischitta V
Published: January 2005

OBJECTIVE: The 'standard' postoperative follow-up of patients with differentiated thyroid cancer (DTC) has been based upon serum thyroglobulin (Tg) measurement and (131)I whole body scan ((131)I-WBS) after thyroid hormone (T(4)) treatment withdrawal. However, (131)I-WBS sensitivity has been reported to be low. Thyroid hormone withdrawal, often associated with hypothyroidism-related side effects, may now be replaced by recombinant human thyroid stimulating hormone (rhTSH). The aim of our study was to evaluate the diagnostic accuracy of (131)I-WBS and serum Tg measurement obtained after rhTSH stimulation and of neck ultrasonography in the first follow-up of DTC patients. DESIGN: Ninety-nine consecutive patients previously treated with total thyroidectomy and (131)I ablation, with no uptake outside the thyroid bed on the post-ablative (131)I-WBS (low-risk patients) were enrolled. METHODS: Measurement of serum Tg and (131)I-WBS after rhTSH stimulation, and ultrasound examination (US) of the neck. RESULTS: rhTSH-stimulated Tg was 1 ng/ml (Tg+) in 21 patients, including 6 patients with Tg levels >5 ng/ml. (131)I-WBS was negative for persistent or recurrent disease in all patients (i.e. sensitivity = 0%). US identified lymph-node metastases (confirmed at surgery) in 4/6 (67%) patients with stimulated Tg levels >5 ng/ml, in 2/15 (13%) with Tg>1<5 ng/ml, and in 2/78 (3%) who were Tg-negative. CONCLUSIONS: (i) diagnostic (131)I-WBS performed after rhTSH stimulation is useless in the first follow-up of DTC patients; (ii) US may identify lymph node metastases even in patients with low or undetectable serum Tg levels.
Gene therapy of thyroid cancer via retrovirally-driven combined expression of human interleukin-2 and herpes simplex virus thymidine kinase
Authors: Barzon L , Bonaguro R , Castagliuolo I , Chilosi M , Franchin E , Del Vecchio C , Giaretta I , Boscaro M , Palu G
Published: January 2005

OBJECTIVE AND DESIGN: Based on our clinical experience with combined gene therapy of glioblastoma, we developed a retroviral vector expressing two therapeutic genes (i.e. thymidine kinase of herpes simplex virus, HSV-TK, and interleukin-2, IL-2) and evaluated its efficiency in vitro and in vivo. METHODS: Expression of therapeutic genes in transduced thyroid carcinoma cells was analyzed by real-time RT-PCR. Ganciclovir sensitivity of infected cells was assessed in vitro in thyroid carcinoma cell lines and in vivo in nude mice bearing xenografted thyroid cancers. The combined effect of IL-2/HSV-TK was compared with the effect of IL-2 alone. RESULTS: Expression of therapeutic genes was higher in differentiated than in anaplastic thyroid carcinoma cells. Ganciclovir treatment led to dose- and time-dependent killing of transduced cells in vitro. A bystander effect was demonstrated by using mixtures of infected and non-infected cells. In vivo studies showed a significant reduction of growth and the presence of an inflammatory infiltrate in transduced thyroid tumors expressing IL-2 alone, as compared with non-infected tumors. By using the retroviral vector expressing IL-2/HSV-TK, treatment with ganciclovir led to complete eradication of anaplastic tumors and a >80% reduction of the size of differentiated thyroid carcinomas. Histological analysis of tumor specimens showed extensive necrosis and inflammatory cell infiltrates. The combination of IL-2/HSV-TK plus ganciclovir was significantly more efficient than IL-2 alone in eradicating tumor masses. The bystander effect was also obtained in vivo. CONCLUSIONS: These findings demonstrate the feasibility and efficiency of a combined immunomodulating and suicide gene therapy approach for thyroid carcinomas.
Immunohistochemical detection of cell cycle regulators, Fhit protein and apoptotic cells in parathyroid lesions
Authors: Thomopoulou GE , Tseleni-Balafouta S , Lazaris AC , Koutselini H , Kavantzas N , Davaris PS
Published: January 2005

OBJECTIVE: The pathological distinction between parathyroid neoplasms and hyperplasias remains difficult. Changes in cell cycle control may lead to clonal proliferation and precede tumorigenesis. The parathyroid adenoma 1 oncogene, subsequently identified as the gene encoding cyclin D1, has been shown to be important to parathyroid tumour development. In addition to cell proliferation, the mechanisms of parathyroid cell turnover include apoptosis. The tumour-suppressor activity of the fragile histidine triad gene (FHIT) is linked to its proapoptotic function and cell cycle control. We attempted to evaluate the cellular proliferative kinetics and apoptotic function of the parathyroid glands in patients with non-familial hyperparathyroidism (HPT). DESIGN: TIssue specimens were taken from 40 patients with primary HPT (17 adenomas, two carcinomas and 21 primary hyperplasias) and from 30 patients with secondary HPT. Normal glands served as controls. METHODS: In a standard immunohistochemical procedure, monoclonal antibodies to Ki-67 antigen and single-stranded DNA were applied to detect cycling and apoptotic cells respectively; polyclonal antibodies to cyclin D1 and Fhit protein were used. Immunostaining was estimated by image analysis and statistical analysis was subsequently performed. RESULTS: Significantly higher proliferative and apoptotic indexes were detected in the diseased glands in comparison with normal controls. In neoplastic and secondarily hyperplastic glands, apoptotic indexes were higher than in primarily hyperplastic glands; the difference between neoplastic and primarily hyperplastic glands was statistically significant (P=0.034). Cyclin D1 was overexpressed in a considerable proportion of tumours (68.4%). A reduction of Fhit protein immunoreactivity was selectively noticed in carcinomas. CONCLUSIONS: In primary hyperplasia, the remarkable proliferation of parathyroid glands may be due to the reduction of the apoptotic process. FHIT gene abnormalities are worthy of investigation in parathyroid carcinogenesis.
Is programming of glucocorticoid receptor expression by prenatal dexamethasone in the rat secondary to metabolic derangement in adulthood?
Authors: Cleasby ME , Livingstone DE , Nyirenda MJ ,   Seckl, Walker BR
Published: January 2005

OBJECTIVE: Glucocorticoids may contribute to the association between retarded growth in utero and insulin resistance in adulthood. Administration of dexamethasone (dex) to pregnant rats results in low birth weight offspring, which develop glucose intolerance, hyperinsulinaemia and hypercorticosteronaemia. This may be explained by tIssue-specific differences in expression of glucocorticoid receptors (GR) in adult offspring: GR is increased in visceral fat and liver, and decreased in hippocampus and soleus muscle. However, cause and effect between altered GR expression, hypercorticosteronaemia, and hyperinsulinaemia remains to be established. DESIGN AND METHODS: Rats were treated with dex (100 microg/kg per day) or saline during the third week of pregnancy. In 5-8-Month-old male offspring, GR expression in insulin target tIssues was quantified by RNase protection assay in rats that were adrenalectomised (ADX group), sham operated (SHAM group), or adrenalectomised with supra-physiological corticosterone replacement (CORT group) (n=7-8 per group), and in rats treated orally with vehicle, metformin (43 mg/kg per day) or rosiglitazone (1 mg/kg per day), after 3 weeks. RESULTS: Manipulation of corticosterone concentration did not affect GR mRNA in skeletal muscle or adipose. In liver, sham-operated animals showed lower GR mRNA, but there was no difference between adrenalectomised and hypercorticosteronaemic animals (SHAM 0.11+/-0.01 ratio to beta-actin, vs ADX 0.22+/-0.02, CORT 0.23+/-0.02, (values expressed as means+/-s.e.m.), P<0.001). Rosiglitazone reduced GR mRNA by approximately 30% in liver of dex- and saline-treated offspring (P<0.05), but had no effect on GR in adipose and skeletal muscle. Metformin abolished the 38% up-regulation of liver GR mRNA induced by antenatal dex and also reduced GR mRNA preferentially in muscle of dex-treated animals (0.14+/-0.01 vs 0.10+/-0.01; P=0.03). CONCLUSIONS: We conclude that neither hypercorticosteronaemia nor hyperinsulinaemia are sufficient to cause the changes in GR expression in dex-programmed rats, implying that these changes may be primary in determining the programmed insulin resistant phenotype. Normalisation of GR expression by metformin may be important in the mode of action of this anti-diabetic agent and may be especially useful to reverse-programmed up-regulation of GR.
High glucose and insulin in combination cause insulin receptor substrate-1 and -2 depletion and protein kinase B desensitisation in primary cultured rat adipocytes: possible implications for insulin resistance in type 2 diabetes
Authors: Buren J , Liu HX , Lauritz J , Eriksson JW
Published: January 2005

OBJECTIVE: The purpose of this study was to investigate the cellular effects of long-term exposure to high insulin and glucose levels on glucose transport and insulin signalling proteins. DESIGN AND METHODS: Rat adipocytes were cultured for 24 h in different glucose concentrations with 10(4) microU/ml of insulin or without insulin. After washing, (125)I-insulin binding, basal and acutely insulin-stimulated d-[(14)C]glucose uptake, and insulin signalling proteins and glucose transporter 4 (GLUT4) were assessed. RESULTS: High glucose (15 and 25 mmol/l) for 24 h induced a decrease in basal and insulin-stimulated glucose uptake compared with control cells incubated in low glucose (5 or 10 mmol/l). Twenty-four hours of insulin treatment decreased insulin binding capacity by approximately 40%, and shifted the dose-response curve for insulin's acute effect on glucose uptake 2- to 3-fold to the right. Twenty-four hours of insulin treatment reduced basal and insulin-stimulated glucose uptake only in the presence of high glucose (by approximately 30-50%). At high glucose, insulin receptor substrate-1 (IRS-1) expression was downregulated by approximately 20-50%, whereas IRS-2 was strongly upregulated by glucose levels of 10 mmol/l or more (by 100-400%). Insulin treatment amplified the suppression of IRS-1 when combined with high glucose and also IRS-2 expression was almost abolished. Twenty-four hours of treatment with high glucose or insulin, alone or in combination, shifted the dose-response curve for insulin's effect to acutely phosphorylate protein kinase B (PKB) to the right. Fifteen mmol/l glucose increased GLUT4 in cellular membranes (by approximately 140%) compared with 5 mmol/l but this was prevented by a high insulin concentration. CONCLUSIONS: Long-term exposure to high glucose per se decreases IRS-1 but increases IRS-2 content in rat adipocytes and it impairs glucose transport capacity. Treatment with high insulin downregulates insulin binding capacity and, when combined with high glucose, it produces a marked depletion of IRS-1 and -2 content together with an impaired sensitivity to insulin stimulation of PKB activity. These mechanisms may potentially contribute to insulin resistance in type 2 diabetes.
A polymorphism in the IGF-I gene influences the age-related decline in circulating total IGF-I levels
Authors: Rietveld I , Janssen JA , Hofman A , Pols HA , van Duijn CM , Lamberts SW
Published: January 2005

OBJECTIVE: Recent studies have demonstrated an association between a 192 bp polymorphism of the IGF-I gene and total IGF-I serum levels, birth weight, body height and the risk of developing diabetes and cardiovascular diseases later on in life. This IGF-I gene polymorphism in the promoter region of the IGF-I gene may directly influence the expression of IGF-I. In the present study we evaluated the role of this polymorphism in the age-related decline in serum IGF-I levels. SUBJECTS AND METHODS: All subjects were participants of the Rotterdam Study, a population-based cohort study of diseases in the elderly. We studied a total group of 346 subjects, who comprised two subgroups: a randomly selected population-based sample of 196 subjects, and a group of 150 subjects selected on IGF-I genotype. In the total group of 346 individuals the relationship between this 192 bp polymorphism and the age-related decline in circulating total IGF-I levels was studied. RESULTS: Homozygous carriers of the 192 bp allele demonstrated significant decline in serum IGF-I with age (r=-0.29, P=0.002). This decline is similar to that seen in the general population. An age-related decline in serum total IGF-I was not observed in heterozygotes (r=-0.06, P=0.48) and non-carriers (r = -0.12, P=0.32). Interestingly, the relationship between age and serum IGF-binding protein-3 levels showed the same pattern. CONCLUSION: We observed only in homozygous carriers of the 192 bp alleles of the IGF-I gene an age-related decline in circulating total IGF-I levels, but not in heterozygotes and non-carriers of the 192 bp allele. We hypothesize that this IGF-I gene polymorphism directly or indirectly influences GH-mediated regulation of IGF-I secretion.
Diurnal rhythm of free estradiol during the menstrual cycle
Authors: Bao AM , Liu RY , van Someren EJ , Hofman MA , Cao YX , Zhou JN
Published: January 2005

OBJECTIVE: To investigate the diurnal rhythm of estrogens in normally cyclic women during reproductive life. DESIGN: Multiple saliva sampling in normally cyclic healthy women during reproductive life at different phases of their menstrual cycles was carried out. METHODS: Salivary estradiol was measured by radioimmunoassay in samples collected every 2 h for 24 h from 15 normally cyclic healthy women during reproductive life during the menstrual phase, the late follicular/peri-ovulation phase, the early to mid luteal phase and the late luteal phase, respectively, of their menstrual cycles. The levels of salivary estradiol were analyzed by means of periodic regression. RESULTS: A daily biological rhythm of free estradiol was found after quantification with a nonlinear periodic regression model. The observed diurnal free estradiol rhythm consists of two major components: an asymmetrically peaked diurnal cycle and ultradian harmonics in the range of 6 to 12 h. The diurnal and ultradian rhythms were remarkably consistent throughout the menstrual cycle in terms of mesor (24 h mean level), peak width and amplitude. There was a tendency for the 24-h rhythm acrophases to converge in the early morning, while the acrophase of the menstrual phase occurred significantly later than in the late follicular/peri-ovulation phase. CONCLUSIONS: The diurnal rhythm of estradiol has a similar complex temporal organization for different menstrual phases. The menstrual cycle mainly modulates the acrophase of the diurnal rhythm.
A prospective study of thyroid function, morphology and autoimmunity in young patients with type 1 diabetes
Authors: Hansen D , Bennedbaek FN , Hoier-Madsen M , Hegedus L , Jacobsen BB
Published: January 2005

OBJECTIVE: Thyroid autoantibodies (TA) and thyroid ultrasonography are widely used in the diagnosis of autoimmune thyroid disease (AITD). However, we know little of the significance of having ultrasonographic abnormalities (USabn) without having any other signs of AITD. In a previous population-based study of 105 young patients with type 1 diabetes (T1DM) we found a high prevalence (42%) of USabn. In the present study we evaluate the development of both USabn and TA in a 3-Year follow-up of this cohort. DESIGN: Of the 105 previously investigated children and adolescents with T1DM (aged 5-21 Years), 101 were re-examined. Serum concentrations of tri-iodothyronine (T(3)), thyroxine (T(4)), TSH, thyroid peroxidase antibodies (TPOab) and thyroglobulin antibodies (Tgab), as well as thyroid size and morphology were determined in all patients. RESULTS: During the 3 Years follow-up period, the prevalence of thyroid dysfunction increased from 5 to 8%, the prevalence of TPOab was unchanged at 13%, while the prevalence of Tgab decreased from 14 to 7%. The prevalence of USabn increased from 42 to 49%. Most patients presented USabn at both examinations. Patients with USabn had a higher prevalence of TA than those without USabn (P=0.038) and higher serum levels of TSH (P=0.027). All patients with thyroid dysfunction presented with USabn. However, many patients with USabn had no other signs of AITD. CONCLUSIONS: A high prevalence of thyroid dysfunction, TA and thyroid USabn were found in young patients with T1DM. Thyroid USabn was a sensitive but non-specific marker of AITD and is therefore unsuitable for screening purposes. Instead, we recommend regular screening using serum TSH in the follow-up of young diabetic patients.
Ectopic TSH-secreting pituitary adenoma of the vomerosphenoidal junction
Authors: Pasquini E , Faustini-Fustini M , Sciarretta V , Saggese D , Roncaroli F , Serra D , Frank G
Published: January 2005

OBJECTIVE: We describe an unusual case of ectopic TSH-secreting pituitary adenoma arising from the vomerosphenoidal junction. CLINICAL PRESENTATION: A 52-Year-old man with a long-standing history of hyperthyroidism was referred to the University Hospital in September 2001 because of increasingly disabling symptoms of nasal obstruction. For the past 18 Years the patient had complained of palpitations, hypertension, weight loss, and nervousness. A presumptive diagnosis of Graves' disease was made. Treatment with methimazole was begun, but the patient was lost to follow-up. On admission, physical examination revealed signs of hyperthyroidism and a large diffuse goiter. Tests of thyroid function showed inappropriate secretion of TSH with hyperthyroidism. Both a TSH-secreting pituitary adenoma and resistance to thyroid hormone could be taken into account. There was no evidence of pituitary tumour by magnetic resonance imaging (MRI), but a large space-occupying lesion involving the nasal cavity and the nasopharynx was incidentally discovered. INTERVENTATION AND TECHNIQUE: Using an endoscopic endonasal approach, the tumour was removed en bloc together with the sphenoid floor, sphenoid rostrum, bony septum, and part of the soft palate mucosa. Histological features and immunophenotype were those of a TSH-secreting tumour. CONCLUSION: Although exceedingly rare, ectopic TSH-secreting pituitary tumour should be borne in mind in cases of inappropriate secretion of TSH with hyperthyroidism and no evidence of pituitary tumour by computed tomography and/or MRI when a mass located along the migration path of the Rathke's pouch is demonstrated by radiological examination. To our knowledge, this is only the second reported case in the literature.
Immunohistochemical detection of FGF-23 protein in tumors that cause oncogenic osteomalacia
Authors: Larsson T , Zahradnik R , Lavigne J , Ljunggren O , Juppner H , Jonsson KB
Published: January 2005

OBJECTIVE: Oncogenic hypophosphatemic osteomalacia (OOM) is a rare disease characterized by hypophosphatemia, inappropriately low levels of circulating 1,25-dihydroxyvitamin D(3) and osteomalacia. The disease is most commonly caused by benign mesenchymal tumors that produce, among several other factors, fibroblast growth factor-23 (FGF-23). Current evidence thus suggests that this protein has an important role in the regulation of phosphate homeostasis. By producing polyclonal antibodies against human FGF-23 protein we wanted to determine the localization of FGF-23 protein in OOM tumors that express FGF-23 mRNA. DESIGN AND METHODS: Three polyclonal antibodies were raised in rabbits against three different peptides with sequences derived from human FGF-23: [Cys-70]FGF-23(51-69)amide, [Tyr-223]FGF-23(206-222)amide and [Tyr-224]FGF-23(225-244)amide. One of the resulting antisera was subsequently used for immunohistochemistry on sections from five different tumors causing OOM. FGF-23 mRNA expression was confirmed with in situ hybridization. RESULTS: After affinity purification, two of three antisera detected recombinant human FGF-23 by Western blot analysis. Through immunohistochemical analysis using the anti-[Tyr-224]FGF-23(225-244)amide antibody and through in situ hybridization using full-length antisense FGF-23 cRNA as a probe, we showed that abundant amounts of FGF-23 protein and mRNA are present in certain tumor cells of five different OOM tumors. CONCLUSIONS: We conclude that OOM tumors express FGF-23 protein and that the immunohistochemical detection of FGF-23 in OOM tumors is feasible and may help in establishing the diagnosis of tumor-induced hypophosphatemia through analysis of biopsies or surgical specimens.