bluuebunny/crossref_metadata_2025 huggingface dataset:
The in vitro secretion of human leptin is gender-dependent but independent of the body mass index of the donors
Authors: Menendez C , Baldelli R , Lage M , Casabiell X , Pinero V , Solar J , Dieguez C , Casanueva FF
Published: January 2005

OBJECTIVE: Leptin is an adipocyte-secreted hormone acting as a signal to the central nervous system, where it regulates energy homeostasis and neuroendocrine processes. Leptin plasma levels are mainly regulated by the percentage of body fat, but are also controlled by several metabolic and nutritional variables. Data regarding leptin secretion suggest that it is gender regulated, and higher levels are present in women than men; however, the biological basis for this sex-related difference is unknown. To clarify those points, a systematic study with tissue cultures from human omental adipose tissue was performed. DESIGN AND METHODS: Surgically obtained samples from 137 patients (68 women, 69 men) were evaluated. The assay was standardized in periods of 24 h ending at 96 h. Each adipose tissue sample from a single donor was incubated in triplicate and leptin results expressed as the mean of the integrated secretion into the medium (nanograms of leptin/g tissue per time). RESULTS: Tissue adipose cultures showed a steady leptin secretion throughout the 96 h studied, with the peak of secretory activity reached at 48 h; afterwards, the in vitro secretion reached a plateau state. Spontaneous leptin secretion in the 24 h and 48 h period, as well as the area under the curve analyzed in the 0-48 h period, showed a gender-based difference that was significantly (P<0. 05) higher in women than in men. When data of spontaneous leptin secretion were correlated with the body mass index (BMI) of the donors, no correlation was found. This suggests that in vivo leptin levels are dependent on the total amount of fat of the individual, but independent of the leptin secretory rate by the adipose tissue of the donor. CONCLUSIONS: Leptin secretion from omental adipose tissue in vitro is: (i) significantly higher in samples from women than in samples from men; and (ii) not correlated with the BMI, showing that in vitro leptin secretion is not related to the adiposity of the donor.
Thyroid ultrasound compared with World Health Organization 1960 and 1994 palpation criteria for determination of goiter prevalence in regions of mild and severe iodine deficiency
Authors: Zimmermann M , Saad A , Hess S , Torresani T , Chaouki N
Published: January 2005

Objectives

In 1994, WHO/International Council for the Control of Iodine Deficiency Disorders recommended replacing the WHO 1960 four-grade goiter classification with a simplified two-grade system. The effect of this change in criteria on the estimation of goiter prevalence in field studies is unclear. In areas of mild iodine deficiency disorders (IDD) where goiters are small, ultrasound is preferable to palpation to estimate goiter prevalence. However, in areas of moderate to severe IDD, goiter screening by palpation may be an acceptable alternative to thyroid ultrasound. To address these two issues, we compared WHO 1960 and 1994 criteria with thyroid ultrasound for determination of goiter prevalence in areas of mild and severe IDD in Morocco.

Design

A cross-sectional study of 400 six- to 13-year-old children from two mountain villages (Ait M'hamed and Brikcha) in rural Morocco was carried out.

Methods

Urinary iodine concentration (UI), whole blood TSH and serum thyroxine were measured. Thyroid size was graded by inspection and palpation by two examiners using both WHO 1960 and 1994 criteria. Thyroid volume was determined by ultrasound. Variation between examiners and examination methods was assessed. Sensitivity and specificity of the two classification systems compared with ultrasound were calculated.

Results

Median UIs in Ait M'hamed and Brikcha were 183 and 24 microg/l respectively. In Ait M'hamed, using 1960 and 1994 criteria, goiter prevalence was 21 and 26% respectively, compared with 13% by ultrasound. In Brikcha, with 1960 and 1994 criteria, goiter prevalence was 64 and 67% respectively, compared with 64% by ultrasound. Agreement between observers was better with the 1994 criteria than with the 1960 criteria in Ait M'hamed (kappa=0.53 and 0.47 respectively), while in Brikcha observer agreement was similar with the two systems (kappa=0.67). Using either the 1994 or 1960 criteria, agreement with ultrasound was only moderate in Ait M'hamed (kappa=0.41-0.44), but good in Brikcha (kappa=0.55-0.64). Overall, compared with ultrasound, sensitivity increased 3-4% using 1994 criteria, while specificity decreased 4-5%.

Conclusions

The WHO 1994 criteria are simpler to use than the 1960 criteria and provide increased sensitivity with only a small reduction in specificity. Agreement between observers is better with the 1994 criteria than with the 1960 criteria, particularly in areas of mild IDD. Like the 1960 criteria, the 1994 criteria overestimate goiter prevalence in areas of mild IDD, compared with ultrasound. However, the 1994 palpation criteria provide an accurate estimate of goiter prevalence in areas of severe IDD, and may be an acceptable and affordable alternative to thyroid ultrasound in these areas.
Changes in plasma thyroid hormone levels after a single dose of triiodothyronine in premature infants of less than 30 weeks gestational age
Authors: Cools F , van Wassenaer A G , Kok J H , de Vijlder J J
Published: January 2005

Objective

Evaluation of thyroid hormone response to a single administration of triiodothyronine (T3) early postnatally to premature infants of <30 weeks gestational age.

Design

A prospective clinical trial with historical control.

Methods

Ten infants born <28 weeks gestational age and ten infants born between 28 and 30 weeks gestational age were given 0.5 microg/kg T3 intravenously at 12 h after birth. The infants <28 weeks gestational age were also treated with thyroxine (T4; 8 microg/kg, once daily) during the first 6 weeks of life. Premature infants from a previous trial served as a matched historical control group. Analysis of variance for repeated measurements was performed.

Results

For the infants <28-30 weeks gestational age mean plasma T3 concentrations were significantly higher in the T3-treated group (P=0.027) for at least 2 weeks, whereas mean plasma levels of T4, free T4 and TSH were comparable. For the infants <28 weeks gestational age plasma T3 levels were also significantly different after correction for gestational age (P=0.0002), with either comparable or higher values in the T3-treated infants up to 56 days after injection of T3. Mean plasma free T4 levels were lower during the first 3 days and higher or comparable thereafter (P=0.0014), and TSH suppression was more evident in the T3-treated infants (P=0.003)

Conclusion

A single administration of T3 to premature infants <30 weeks gestational age early postnatally results in a sustained increase of plasma T3 levels during the first weeks of life. In infants of 28-30 weeks gestational age this occurs without change in plasma free T4 levels, whereas in infants <28 weeks gestational age a transient decrease of plasma free T4 was present. The increase in plasma T3 is possibly caused by a T3-induced increase of type I deiodinase activity.
High frequency of antithyroid autoantibodies in pregnant women at increased risk of gestational diabetes mellitus
Authors: Olivieri A , Valensise H , Magnani F , Medda E , De Angelis S , D'Archivio M , Sorcini M , Carta S , Baccarini S , Romanini C
Published: January 2005

Background

Thyroid autoantibodies (ThyAb) and subclinical hypothyroidism occur more frequently in pregnant women with insulin-dependent diabetes mellitus than in healthy pregnant women. Few studies have investigated the presence of ThyAb in women with gestational diabetes mellitus (GDM), and no significant association between diabetes in pregnancy and thyroid function has been reported.

Objective

To assess the thyroid biochemical profile and estimate the prevalence of ThyAb in a group of pregnant women at increased risk of GDM due to family and personal risk factors, and to investigate the relationship between a positive family history of diabetes or thyroid diseases and the eventual presence of ThyAb during pregnancy.

Methods

Oral glucose tolerance, serum ThyAb and thyroid function were evaluated in 181 pregnant women with increased risk for GDM (study group). Seventeen healthy pregnant women without risk factors for GDM and with a normal glucose tolerance were recruited as controls.

Results

The women who developed GDM showed a mean free thyroxine concentration significantly lower than that observed in the healthy pregnant women and in those with impaired gestational glucose tolerance and normal glucose tolerance. Twenty-nine of the 181 women in the study group (16%) were ThyAb positive. However, the risk of being ThyAb positive during pregnancy was three times greater in the women with positive family history of both diabetes mellitus and thyroid disease than in those with no family history of these conditions.

Conclusions

This study showed that women with increased risk of GDM, mostly those with family history of diabetes mellitus and thyroid disease, also have an increased risk of being ThyAb positive during pregnancy. It also highlighted the importance of evaluating thyroid function in pregnant women with impaired glucose tolerance, in view of their increased risk of subclinical hypothyroidism.
Controversies in the evolution of paediatric-adolescent varicocele: clinical, biochemical and histological studies
Authors: Fideleff H L , Boquete H R , Suarez M G , Ruibal G F , Sobrado P G , Azaretsky M , Pujol A B , Sequera A M , Giuseppucci J , Ponzio R
Published: January 2005

Objective

To study hormonal and histological parameters of paediatric-adolescent varicocele in order to know certain aspects of its natural history, in an attempt to find prognostic markers of testicular damage.

Design and Methods

In a prospective cross-sectional study, we evaluated 93 children and adolescents with left unilateral varicocele and 29 healthy males as control group. All of them were classified according to Tanner stage. Scrotal Doppler in both testes and GnRH and human chorionic gonadotrophin (hCG) tests were performed in all subjects. Surgery was performed in 28 patients and homolateral testicular biopsy in 18.

Results

Hormonal measurements of patients with varicocele were compared with a control group for each Tanner stage. Testicular biopsy specimens were analysed by light and electron microscopy. We only observed statistical differences in Tanner III patients in basal FSH (median and range) controls=1.70 (1.10-3.70) IU/l vs varicocele=4.20 (1.00-7.50) IU/l, P<0.05 and in Tanner IV patients in LH post-GnRH: controls=11.0 (7.50-15.0) IU/l vs varicocele=18.0 (5.10-29.0) IU/l, P<0.05 and in testosterone post-hCG: controls=9.50 (7.7-10.0) ng/ml vs varicocele=12.0 (6.2-23.0) ng/ml, P<0.01. No correlation was found between the various clinical grades of varicocele and hormonal measurements for each Tanner stage. No statistically significant differences were found between pre- and post-operative hormonal findings, either in basal levels or in maximal responses. On the other hand, no morphological abnormalities were observed by electron microscopy in germ cells, tubular wall and interstice.

Conclusions

There appears to be no reliable biochemical marker in children and adolescents that may predict impaired testicular function. A significant size discrepancy between both testes, testicular pain and a hyperresponse to GnRH stimulation should continue to be, for the time being, the indications for surgery.
Genomic organization of the 5' region of the human thyroglobulin gene
Authors: Moya C M , Mendive F M , Rivolta C M , Vassart G , Targovnik H M
Published: January 2005

Objective

The purpose of the present work is to establish the intron-exon organization from exon 12 to exon 23 of the human thyroglobulin gene and to construct a physical map of the 5' terminal half of the gene.

Design

Screening of a genomic library and subsequent restriction map, hybridization and sequencing methods have been employed to characterize the recombinant positive phages.

Methods

A human genomic DNA library was screened by in situ hybridization. Southern blotting experiments were performed to characterize the phage inserts. Intron/exon junction sequences were determined by the Taq polymerase-based chain terminator method. Finally, the thyroglobulin gene was mapped using the Gene Bridge 4 radiation hybrid clone panel.

Results

We isolated and characterized four lambda phage clones that include nucleotides 3002 to 4816 of the thyroglobulin mRNA, encompassing exons 12 to 23 of the gene. The exon sizes range between 78 and 219 nucleotides. We found that the GT-AG splicing sequences rule was perfectly respected in all the introns. A total of 7302 intronic bases was analyzed. Hormogenic tyrosine 5 and 1291 are encoded by exons 2 and 18. Also, seven alternative spliced variants are associated with the 5' region. Thyroglobulin gene maps to 5,5 centiRays from the AFMA053XF1 marker, in chromosome 8.

Conclusions

The present study shows that the first 4857 bases of thyroglobulin mRNA are divided into 23 exons and the four phages isolated include 32.6 kb genomic DNA, covering 1815 nucleotides of exonic sequence distributed in 12 exons, from exon 12 to 23.
Stimulation of pregnenolone metabolism and aromatase activity by luteinizing hormone in mouse uterus
Authors: Debnath S , Mukherjee D , Bhattachryya S P
Published: January 2005

In vitro metabolism of pregnenolone (P5) as well as production of 17beta-estradiol (E2) were studied in uteri of untreated and luteinizing hormone (LH)-treated mice that had been ovariectomized (OVX) at late-diestrus stage. In the uteri of untreated mice, [H]pregnenolone was shown to be metabolized to Delta-components such as 17alpha-hydroxypregnenolone (17alpha-P5) and dehydroepiandrosterone (DHEA), whereas LH treatment resulted in significant increases in the formation of progesterone (P4), 17alpha-hydroxyprogesterone (17alpha-P4), androstenedione (AD) and testosterone (T). This was assessed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The content and release of P4 was shown to be stimulated by LH. Trilostane, an inhibitor of 3beta-hydroxysteroid dehydrogenase (3beta-HSD), inhibited LH-induced P4 synthesis and its release in a dose-dependent manner. A considerable increase in [H]estradiol formation from [H]testosterone was recorded in LH-stimulated uterine tissue as compared with the control, indicating the stimulatory effect of LH on aromatase activity. LH-stimulation in the synthesis of P4 and E2 in OVX mouse uteri was mimicked by dbcAMP (cell-permeable cAMP). Incubation with LH was shown to augment the conversion of P4 to various delta-3-oxosteroids. In vitro effects of LH on the synthesis and metabolism of P4, as well as on the stimulation of aromatase activity, were more pronounced in the uterine tissue of LH-primed OVX mice. Thus the results of the present study indicate that, under specific conditions, the uterus of the mouse behaves like steroidogenic tissue. Its prompt response to LH reveals the probable physiological relevance of the existence of LH receptors of high binding affinity in the uterine tissue of the mouse, as reported earlier.
The nuclear, 75 kDa form of early growth response protein-1/nerve growth factor-induced A protein is primarily restricted to LH beta-subunit-expressing cells in rat anterior pituitary
Authors: Knight C , Slade J P , Carter D
Published: January 2005

Objective

Early growth response protein-1 (Egr-1)/nerve growth factor-induced A (also known as Zif-268, Krox-24, TIS8, ZENK) is a zinc-finger transcription factor which, although expressed in a range of organ systems, has been shown to be essential only in the maintenance of fertility through actions within the endocrine system. In the present study we have investigated the anatomical basis for actions of Egr-1 in the adult anterior pituitary gland.

Design

Using female rats and mice as experimental models, we have used immunocytochemical and microscopic analysis to make observations of the cellular and sub-cellular localization of Egr-1 protein.

Methods

Immuno-(Western) blotting was first used to characterize the anterior pituitary proteins detected by a commercially available Egr-1 antibody. Subsequently, the antibody was used both singly and in combination with an LH beta-subunit antibody, for immunocytochemical localization studies in pituitary sections.

Results

The Egr-1 antiserum detected a single, major (primarily nuclear) 75 kDa protein band in Western blots of anterior pituitary extracts. Nuclear localization was confirmed by immunocytochemistry, which also demonstrated that the 75 kDa protein is localized to a minority sub-population of anterior pituitary cells in both rat and mouse. Dual immunocytochemical localization showed that the Egr-1 protein is primarily restricted to the nuclei of LH beta-subunit-expressing cells.

Conclusions

Sub-cellular localization of Egr-1 to the nucleus is consistent with a direct role in transcriptional regulation of anterior pituitary function in the adult rat. Furthermore, a selective role in the physiological control of gonadotrophin gene expression is indicated.
Evaluation of plasma insulin-like growth factor binding protein-2 as a marker for adrenocortical tumors
Authors: Boulle N , Baudin E , Gicquel C , Logie A , Bertherat J , Penfornis A , Bertagna X , Luton JP , Schlumberger M , Le Bouc Y
Published: January 2005

OBJECTIVE: Recent studies have pointed to the role of the IGF system in the pathogenesis of adrenocortical tumors, and it was shown recently that malignant adrenocortical tumors exhibit a high insulin-like growth factor binding protein (IGFBP)-2 content. Circulating markers specific for adrenocortical carcinoma are needed and the aim of this study was to evaluate plasma IGFBP-2 as a marker for these malignant tumors. METHODS: Plasma IGFBP-2 was determined in 51 patients referred to our institutions for adrenocortical tumors. Fifteen patients were in complete remission (group 1), eight patients had preoperative localized tumors (group 2) and 28 patients had metastatic tumors (group 3). Thirty-six healthy volunteers constituted a control group. RESULTS: There was no significant difference in plasma IGFBP-2 concentration between healthy controls and patients with complete remission or localized tumors. In contrast, patients with metastatic disease had significantly higher IGFBP-2 plasma levels than the control group (P<0.001). IGFBP-2 levels in patients with metastatic disease were inversely correlated with survival (R2=0.308; P=0.0026). In patients with localized tumors, there was no correlation between plasma IGFBP-2 concentration and tumor size or histological features. Analysis of individual IGFBP-2 concentrations showed that five patients (17.8%) with metastatic tumors had normal IGFBP-2 levels and two patients (13.3%) in complete remission had high plasma IGFBP-2 levels. The influence of nutrition, hormone secretion and treatment on IGFBP-2 levels was examined. Nutritional status was evaluated by determining IGF-I levels and was found to be normal in 16 patients (61.5%) with high IGFBP-2 levels, suggesting that malnutrition was not responsible for the high IGFBP-2 concentrations in these patients. IGFBP-2 levels did not differ significantly according to tumor secretion or mitotane treatment. In a follow-up study, plasma IGFBP-2 concentration remained stable in patients with complete remission or stabilized disease and was a late marker of tumor progression in patients with progressive metastatic disease. CONCLUSIONS: These results indicate that plasma IGFBP-2 is elevated in patients with malignant adrenocortical tumors and that the major factor affecting IGFBP-2 levels in these patients is tumor stage. However, plasma IGFBP-2 was less sensitive than expected for a tumor marker, which may limit its value in the diagnosis and follow-up of adrenocortical carcinoma.
Counterregulatory responses to hypoglycemia in patients with maturity-onset diabetes of the young caused by HNF-1alpha gene mutations (MODY3)
Authors: Guenat E , Seematter G , Philippe J , Temler E , Jequier E , Tappy L
Published: January 2005

Mutations of HNF-1alpha lead to severe beta cell dysfunction, resulting in decreased glucose-induced insulin secretion. HNF-1alpha is also expressed in liver, kidney and pancreatic alpha cells, but the functional consequences of HNF-1alpha mutations in these organs remain unknown. We therefore assessed the counterregulatory responses to hypoglycemia in six patients with HNF-1alpha mutations (MODY3), five patients with non-insulin-dependent diabetes mellitus (NIDDM) and in nine healthy controls. Plasma glucagon concentrations and endogenous glucose production were measured every 15 min during a hyperinsulinemic clamp with progressive hypoglycemia. Plasma glucagon concentrations were similar at basal glycemia (73+/-6, 69+/-5 and 69+/-7 ng/l) and reached peak values of 88+/-9, 88+/-11 and 89+/-7 ng/l at a glycemia of 3.6 mmol/l in MODY3 patients, patients with NIDDM and controls respectively (NS). Suppression of endogenous glucose production by insulin was blunted in MODY3 patients (3.3+/-1.2 micromol/kg per min) and in patients with NIDDM (4.4+/-0.6 micromol/kg per min) compared with controls (1.7+/-0.5 micromol/kg per min, P<0.05 compared with both MODY3 patients and patients with NIDDM). During hypoglycemia, endogenous glucose production increased to 8.6+/-2.1, 8.8+/-0.7 and 7.0+/-1.0 micromol/kg per min in MODY3 patients, patients with NIDDM and controls respectively (all NS). These data indicate that mutations of HNF-1alpha in MODY3 do not result in a decreased glucagon secretion or alterations of glucose production during hypoglycemia.
ACTH silent adenoma shrinking under cabergoline
Authors: Petrossians P , Ronci N , Valdes Socin H , Kalife A , Stevenaert A , Bloch B , Tabarin A , Beckers A
Published: January 2005

OBJECTIVES: The authors present a case report that proposes the use of cabergoline treatment in silent ACTH adenoma, an unusual member of the heterogeneous group of the so-called clinically non-functioning pituitary adenomas. DESIGN: Following the clinical and radiological improvement of a recurrent silent ACTH adenoma in a 77-year-old patient treated with cabergoline (0.5 mg every 2 days for 2 years), in vitro studies of the original tumor were performed. METHODS: The original tumor from the patient was studied by in situ hybridization and dopamine D2 receptor autoradiography. It was compared with four macroprolactinomas and two macroadenomas from patients with Cushing's disease. RESULTS: The D2 receptor mRNA signal of the reported case was intense and of the same order of magnitude as that observed in control prolactinomas. Dopamine D2 receptor autoradiography was twice that of control corticotroph adenomas and was close to that observed in prolactinomas. CONCLUSIONS: This is the first description of an in vivo shrinkage of an ACTH silent adenoma under cabergoline. We demonstrate in vitro, the presence of D2 receptors in the primitive tumor in concentrations similar to those found in control prolactinomas. These results suggest that therapeutic trials with cabergoline might be undertaken in recurring cases of ACTH silent tumors and more generally, non-functioning pituitary adenomas.
Expression and localization of activin receptors during endochondral bone development
Authors: Funaba M , Ogawa K , Abe M
Published: January 2005

The expression and localization of activins (dimeric protein of inhibin beta subunit) and activin receptors in skeletal tissue were examined. RT-PCR revealed that cultured chondrocytes expressed mRNAs of inhibin/activin betaA and four activin receptors (two type I (ActRI and ActRIB) and two type II (ActRII and ActRIIB)). Immunohistochemical analyses showed that activin betaA, ActRI and ActRII were localized in proliferating chondrocytes and osteoblasts in tibiae of neonatal rats, and in implants of demineralized bone matrix, a well-established model of ectopic bone formation. The immunoreactivities of osteoblasts were decreased with aging in the tibiae and with progressing endochondral bone development in the implants. The strong expression of ActRI was also detected in hypertrophic chondrocytes both in the tibial growth plate and in the implants, whereas immunoreactive ActRII was lower in hypertrophic chondrocytes. Western blot analysis also showed that immunoreactive ActRI, migrating at 52 kDa, was detected only in the implants on days 9 and 11, the period of conversion from cartilage to bone. In view of the sharing of type II receptors between activins and bone morphogenetic proteins (BMPs), our findings suggest that activin/BMP activity involves in bone modeling, especially during active chondro- and osteogenesis and during the conversion from cartilage to bone.
Differences between the effects of thyroxine and tetraiodothyroacetic acid on TSH suppression and cardiac hypertrophy
Authors: Lameloise N , Siegrist-Kaiser C , O'Connell M , Burger A
Published: January 2005

OBJECTIVE: We earlier reported marked qualitative differences between the effect of 3,5,3'-tri-iodothyroacetic acid (Triac) and tri-iodothyronine (T3) on cardiac hypertrophy at equivalent thyroid-stimulating hormone (TSH)-suppressive doses. We have now extended these studies to specific cardiac parameters. Due to its rapid metabolic clearance rate, Triac is not suitable for TSH suppression and therefore the slowly metabolized 3,5,3',5'-tetraiodothyroacetic acid (Tetrac), the precursor of Triac, was studied. METHODS: Hypothyroid rats were infused over 13 days with 1.5-40.5 nmol Tetrac/day per 100 g body weight (BW) or with 0.5-13.5 nmol thyroxine ((4)T4)/day per 100 g BW. RESULTS: The responses of serum TSH and of hepatic monodeiodinase type 1 were parallel for both hormones, their potency ratios could therefore be compared. Tetrac was revealed as being only half as active on hepatic monoiodinase type 1 despite a similar serum TSH levels. Tetrac can therefore be considered to have a preferential action on serum TSH suppression. The cardiac effects on Ca2+-ATPase (SERCA 2a) and monodeiodinase type 1 activity were qualitatively different and therefore one cannot give an overall quantitative estimate of these differences. The results showed clearly, however, that Tetrac is less efficient for all parameters studied, namely induction of cardiac hypertrophy, alpha-myosin heavy chain mRNA, monodeiodinase type 1 activity and mRNA levels of the sarcoplasmic SERCA 2a. CONCLUSION: We postulate therefore that, in the rat and possibly in man, Tetrac could represent a favorable alternative for suppression of serum TSH levels.
Contrasting effects of nitric oxide on food intake and GH secretion stimulated by a GH-releasing peptide
Authors: Rigamonti AE , Cella SG , Cavallera GM , Deghenghi R , Locatelli V , Pitsikas N , Muller EE
Published: January 2005

OBJECTIVE: Among the many actions of nitric oxide (NO) are those on endocrine and feeding behaviour. Based on NO involvement in the GH-releasing effect of the GH-releasing peptides (GHRPs) and the reported orexigenic activity of these compounds, we sought to evaluate the effect of the combined administration of a long-acting NO donor, molsidomine, and the newly synthesized GHRP EP92632 on food intake and GH secretion in rats. Moreover, to verify the specificity of a potential NO involvement, we evaluated whether or not the effects of GHRPs were abolished by a pre-treatment with an inhibitor of NO synthase, N-nitro-arginine-methyl-ester (NAME). METHODS: In the food intake experiments, adult Sprague-Dawley male rats underwent acute administration of: (1) EP92632 (160 microg/kg, s.c.); (2) molsidomine (100 mg/kg, i.p.); (3) EP92632+molsidomine; (4) l-NAME (40 and 60 mg/kg, i.p.); (5) EP92632+l-NAME (60 mg/kg, i.p.); (6) EP92632+molsidomine+l-NAME (60 mg/kg, i.p.); and (7) 0.9% saline (0.1 ml/kg, i.p.). After treatments, the cumulative food intake in the 6 post-treatment hours was carefully evaluated. In the neuroendocrine experiments, rats were given the same compounds according to the above reported schedule, except for the use of one dose of NAME (60 mg/kg, i.p.) and a lower EP92632 dose (80 microg/kg, s.c.), and were sampled via atrial cannula. RESULTS: EP92632 significantly stimulated food intake, an effect which was further enhanced by molsidomine, though the latter did not elicit per se any orexigenic effect. l-NAME given alone significantly decreased food intake and abolished the orexigenic effect of the GHRP and the enhancing effect of molsidomine. Plasma GH levels increased significantly following administration of EP92632 but, in contrast to the food intake experiments, molsidomine significantly inhibited both basal and EP92632-stimulated GH secretion; moreover, NAME had a biphasic effect on the EP92632-stimulated GH release: initially inhibitory and then, from 45 min on, stimulatory. NAME did not affect basal GH levels but, surprisingly, combined administration of molsidomine and NAME induced a striking inhibition of both basal and the peptide-stimulated GH release. CONCLUSIONS: In summary, these data indicate that NO in the rat is physiologically involved in a stimulatory way in the GHRP-mediated effect on food intake, but exerts a dual action, probably stimulatory at hypothalamic and inhibitory at pituitary levels, on basal and GHRP-stimulated GH secretion.
The pancreatic islets in spontaneously hypertensive rats: islet blood flow and insulin production
Authors: Iwase M , Sandler S , Carlsson PO , Hellerstrom C , Jansson L
Published: January 2005

The aim of the study was to investigate if hypertension affects pancreatic islet blood flow and endocrine function. For this purpose, spontaneously hypertensive rats (SHR) were compared with normotensive control Wistar-Kyoto rats (WKY). Both islet size and islet cell replication in 4-month-old SHR was increased compared with WKY. The (pro)insulin biosynthesis was reduced in islets isolated from SHR, whereas the insulin content was unchanged. A hyperinsulinemic response to glucose in vivo was observed in 4- and 12-month-old SHR. Pancreatic blood flow, measured using a microsphere technique, was lower in SHR than in WKY in rats aged 5 weeks, 4 months or 1 year. Islet blood flow was lower in 4-month-old and 1-year-old SHR. In 4-month-old animals, islet blood flow was unaffected by administration of enalaprilate and prazosin in both strains, but was markedly decreased by the administration of N(G)-methyl-L-arginine. It was concluded that the islets of SHR have a decreased insulin production in vitro and a decreased islet blood perfusion. The reasons for this are likely to be multifactorial. Because SHR maintained an essentially normal glucose tolerance, an adaptation of the beta-cells to the metabolic and hemodynamic changes imposed by hypertension occurred.
Skeletal responsiveness to parathyroid hormone in pseudohypoparathyroidism
Authors: Kanatani M , Sugimoto T , Kaji H , Ikeda K , Chihara K
Published: January 2005

BACKGROUND: Although there have been some case reports suggesting that bone in patients with pseudohypoparathyroidism (PHP) might respond to parathyroid hormone (PTH), no information is available as to whether serum PTH concentration is related to bone metabolic markers or to bone mineral density (BMD) in PHP. OBJECTIVE: To address these relationships, by comparing intact serum PTH, bone metabolic markers and BMD in patients with PHP with those in patients with idiopathic hypoparathyroidism (IHP) and postoperative hypoparathyroidism (OHP). METHODS: Intact serum PTH, bone metabolic markers (osteocalcin, tartrate-resistant acid phosphatase, pyridinoline, deoxypyridinoline) and BMD by dual-energy X-ray absorptiometry or single-photon absorptiometry were measured in patients with PHP Ia (n=2) and PHP Ib (n=8). The results were compared with those in patients with IHP (n=5) and OHP (n=14). RESULTS: All bone metabolic markers measured were present in significantly greater amounts in patients with PHP Ib than in those with IHP+OHP. The Z score (standard deviation of average BMD at each age) of the BMD of femoral neck was significantly lower in patients with PHP Ib than in those with IHP+OHP. The Z scores of BMD of lumbar spine and radius were also lower in patients with PHP Ib than in those with IHP+OHP, but the difference was not significant. Moreover, the intact serum PTH concentrations were significantly and positively related to bone metabolic marker levels in all patients, and the intact serum PTH concentrations were significantly and negatively related to BMD of lumbar spine in PHP patients. CONCLUSIONS: These results suggest that PTH stimulates bone turnover in PHP Ib patients, resulting in a relatively lower BMD in PHP Ib patients than in IHP+OHP patients. The present study indicates that bones of most cases of PHP could respond to PTH.
Abundant expression of platelet-derived growth factor in spiral arteries in decidua associated with pregnancy-induced hypertension and its relevance to atherosis
Authors: Morita H , Mizutori M , Takeuchi K , Motoyama S , Maruo T
Published: January 2005

OBJECTIVE: To elucidate the role of platelet-derived growth factor (PDGF) in the pathophysiology of pregnancy-induced hypertension (PIH) in which the spiral arteries of the decidua demonstrate the atherosclerotic change. DESIGN AND METHODS: We determined serum levels of PDGF and PDGF expression in the decidua as well as serum levels of 17 beta-estradiol (E2) and progesterone (P4) both in normotensive cases and in PIH cases. Furthermore, we investigated whether sex steroid hormones could interact with PDGF in cultured vascular smooth muscle cells (SMC) by immunohistochemical staining for proliferating cell nuclear antigen. RESULTS: Serum PDGF levels were higher (P<0.01) but serum E2 levels were lower (P<0.01) in PIH cases compared with normotensive cases. There was no statistically significant difference between serum P4 levels in PIH cases and those in normotensive cases. Immunohistochemical staining for PDGF in SMC of spiral arteries was more prominent in PIH cases than in normotensive cases. The proliferative potential of cultured SMC was stimulated by PDGF, but inhibited by concomitant treatment with PDGF and E2. CONCLUSIONS: PDGF is suggested to play an important role in the pathophysiology of PIH through its stimulatory effect on vascular SMC proliferation which may elicit the atherosclerotic change in the spiral arteries of the placenta.
A programme of iodine supplementation using only iodised household salt is efficient--the case of Poland
Authors: Szybinski Z , Delange F , Lewinski A , Podoba J , Rybakowa M , Wasik R , Szewczyk L , Huszno B , Golkowski F , Przybylik-Mazurek E , Karbownik M , Zak T , Pantoflinski J , Trofimiuk M , Kinalska I
Published: January 2005

BACKGROUND: Iodine prophylaxis in Poland started in 1935 and has been interrupted twice: by World War II and in 1980 for economic reasons. Epidemiological surveys carried out after the Chernobyl accident in 1989 as well as in 1992/1993 and in 1994 as a 'ThyroMobil' study, revealed increased prevalence of goitre in children and adults. Ninety per cent of Poland was classified as an area of moderate iodine deficiency, and 10%, in the seaside area, as mild iodine deficiency territory. Iodine prophylaxis based on iodisation of household salt was introduced again in 1986 as a voluntary model and in 1997 as a mandatory model with 30+/-10 mg KI/kg salt. OBJECTIVE: The evaluation of the obligatory model of iodine prophylaxis in schoolchildren from the same schools in 1994 and 1999. METHODS: Thyroid volume was determined by ultrasonography. Ioduria in casual morning urine samples was measured using Sandell-Kolthoff's method, within the framework of the ThyroMobil study. RESULTS: Goitre prevalence decreased from 38.4 to 7% and urinary iodine concentration increased from 60.4 to 96.2 microg/l mean values between 1994 and 1999. In four schools the prevalence of goitre diminished below 5%. In 1999, 70% of children excreted over 60 microg I/l, and 36% over 100 microg I/l, whereas in 1994 the values were 44 and 13% respectively. CONCLUSION: The present findings indicate that iodine prophylaxis based only on iodised household salt is highly effective.
Identification of a novel mutation in the autoimmune regulator (AIRE-1) gene in a French family with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy
Authors: Saugier-Veber P , Drouot N , Wolf LM , Kuhn JM , Frebourg T , Lefebvre H
Published: January 2005

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is clinically characterized by the presence of two of the three major clinical symptoms: Addison's disease and/or hypoparathyroidism and/or chronic mucocutaneous candidiasis. Because of its autosomal recessive inheritance, this rare disorder constitutes an interesting model for understanding the molecular background of autoimmunity. Recently, mutations in the autoimmune regulator (AIRE-1) gene have been identified in APECED patients. Here we report, in a large French APECED family, the identification of a novel AIRE-1 missense mutation (Pro326Leu) in association with the Arg257Stop mutation which is detected in more than 80% of mutant Finnish AIRE-1 alleles. This Pro326Leu substitution occurs in the first plant homeodomain (PHD)-type zinc-finger domain of the protein which has been identified in a number of nuclear proteins involved in chromatin-mediated transcriptional regulation, such as ATRX, TIF1, KRIP-1 and Mi-2 autoantigen. This mutation highlights the key role of this amino acid in the structure of the PHD domain and confirms that exon 8 constitutes a mutational hotspot.
Decreased pituitary sensitivity to glucocorticoids in endurance-trained men
Authors: Duclos M , Corcuff JB , Pehourcq F , Tabarin A
Published: January 2005

OBJECTIVE: Muscular exercise induces hypothalamo-pituitary-adrenal (HPA) axis activation and when regularly repeated, as in endurance training, leads to HPA axis adaptation. To assess whether non-professional endurance-trained (ET) men with a substantial training load and no clinical or biological features of HPA axis overactivity can present subtle alterations of HPA axis sensitivity to glucocorticoid negative feedback, nine ET men were subjected to HPA axis testing using the dexamethasone-corticotrophin-releasing hormone (CRH) test. DESIGN: Nine endurance-trained men and eight healthy age-matched sedentary men were studied. Morning plasma cortisol and 24 h urinary free cortisol (UFC) were determined and a low dose dexamethasone suppression test (LDDST) was performed followed by CRH stimulation (dexamethasone-CRH test). RESULTS: After a day without physical exercise, at 0800 h, plasma ACTH and cortisol concentrations, and the 24 h UFC and UFC/urinary creatinine (UC) ratio were similar in ET and sedentary men. By contrast, clear differences between the groups were seen in cortisol and ACTH responses to the dexamethasone-CRH test. In eight ET subjects, after LDDST, basal ACTH and cortisol levels were similar to those of sedentary men, whereas one ET subject displayed a poor suppression of cortisol level (131 nmol/l). After injection of CRH, however, three of nine ET men's cortisol levels were not suppressed by dexamethasone but instead displayed significant CRH-induced increase (peak cortisol: 88, 125 and 362 nmol/l). No sedentary subject exhibited any increase in cortisol levels. CONCLUSION: Three of nine ET men with a mean maximum rate of O2 uptake (VO2, max) of 61 ml/kg per min, running 50-70 km per week, were resistant to glucocorticoid suppression during the combined dexamethasone-CRH test.
Vitamin D and estrogen receptor gene polymorphisms in type 2 diabetes mellitus and in android type obesity
Authors: Speer G , Cseh K , Winkler G , Vargha P , Braun E , Takacs I , Lakatos P
Published: January 2005

OBJECTIVE: We studied the significance of BsmI restriction enzyme polymorphism of the vitamin D receptor (VDR) gene and the XbaI and PvuII polymorphisms of the estrogen receptor (ER) gene in patients with type 2 diabetes (n=49), android type obesity with normal carbohydrate metabolism (n=29) and healthy controls (n=138). METHODS: The distribution of genotypes in the study groups, as well as their relationship to fasting and 1 h postprandial serum C-peptide levels were analyzed. RESULTS: Postprandial serum C-peptide levels of BB genotypes were significantly higher in the diabetes and obese groups (6.18+/-5.09 ng/ml) compared with other genotypes (2.71+/-2.45 vs. 1.72+/-1.97 ng/ml, respectively, P=0.05). Among patients with type 2 diabetes and obese subjects, the XX allelic variant of the ER gene was more frequent (P=0.00015). Postprandial C-peptide levels of subjects exhibiting XX genotype were significantly lower compared with those with Xx genotype (1.67+/-2.16 vs. 3.8+/-3.72 ng/ml, P=0.021). The BBXx allelic combination of the VDR/ER receptor genes was less frequent in diabetic patients than in healthy subjects or in obese patients. The BBXx genotype was associated with significantly elevated postprandial C-peptide levels in all subjects compared with other combinations (9.65+/-3.14 vs. 1.35+/-2.82 ng/ml, P=0.003). No difference was found in the distribution of the PvuII polymorphism of the ER gene or in the association with the C-peptide levels among study groups. CONCLUSION: Polymorphisms of the VDR/ER receptor genes might play a role in the pathogenesis of type 2 diabetes by influencing the secretory capacity of beta-cells.
Relationship between free and total 1,25-dihydroxyvitamin D in conditions of modified binding
Authors: van Hoof HJ , de Sevaux RG , van Baelen H , Swinkels LM , Klipping C , Ross HA , Sweep CG
Published: January 2005

OBJECTIVE: A novel assay was employed to study the free 1,25-dihydroxyvitamin D (1,25(OH)2D) concentrations in various populations with different levels of 1,25(OH)2D and vitamin D binding protein (DBP). DESIGN: In 12 healthy women before and after 3 months of oral estrogen/progestagen treatment, 10 pregnant women, and 16 patients with a nephrotic syndrome and normal renal function, the concentrations of total and free 1,25(OH)2D, DBP and albumin were assessed. METHODS: The total concentration of 1,25(OH)2D in serum was assessed using a radioreceptor assay. The free fraction of 1,25(OH)2D was measured using symmetric dialysis. DBP was assessed using single radial immunodiffusion. Serum albumin concentrations were measured on an automated analyzer. RESULTS: In healthy women, the concentrations of total 1,25(OH)2D, free 1,25(OH)2D and DBP were 132+/-19 pmol/l, 92+/-30 fmol/l and 5.59+/-0.43 micromol/l. After 3 months of estrogen/progestagen treatment, total 1,25(OH)2D and DBP levels rose significantly to 175+/-51 pmol/l and 8.32+/-1.59 micromol/l (P< or =0.05 and P< or =0.001); the free 1,25(OH)2D remained unchanged (105+/-39 fmol/l; not significant). Pregnant women had significantly higher levels of total 1,25(OH)2D and DBP (239+/-68 pmol/l and 11.32+/-1.77 micromol/l; both P</=0.001); the free 1,25(OH)2D level, however, was not different (104+/-27 fmol/l; not significant). Unexpectedly, in patients with nephrotic syndrome, no lower DBP levels were found (5.36+/-0.84 micromol/l) relative to that in controls. Despite this, levels of both total (69+/-26 pmol/l, P< or =0.001) and free 1,25(OH)2D (53+/-28 fmol/l; P< or =0.001) were significantly lower than in controls. Albumin levels were lowered from 628+/-38 micromol/l to 300+/-84 micromol/l (P < or = 0.001). CONCLUSIONS: Higher estrogen levels result in higher DBP levels, with a parallel rise in total 1,25(OH)2D levels but without a change in the biologically active free fraction. The results in patients with nephrotic syndrome show that, with increasing glomerular protein leakage, the free 1,25(OH)2D concentration cannot be maintained.
Lectin analyses of glycoprotein hormones in patients with congenital disorders of glycosylation
Authors: Ferrari MC , Parini R , Di Rocco MD , Radetti G , Beck-Peccoz P , Persani L
Published: January 2005

OBJECTIVE: The congenital disorders of glycosylation (CDGs) are progressive multisystemic disorders characterized by a heterogeneous deficiency of the carbohydrate moieties in various structural and circulating glycoproteins, representing a natural model for glycoprotein hormone studies. Here, we studied the carbohydrate moiety of circulating glycoprotein hormones in four patients with a clinical suspicion of CDGs. METHODS: The diagnosis of CDG-I was confirmed in two out of the four cases by transferrin isoelectrofocusing (IEF) and/or carbohydrate-deficient transferrin (CDT) test. The carbohydrate moiety of serum endocrine-related glycoproteins was investigated by means of Ricin (immunopurified thyrotropin (TSH)) and Concanavalin A (Con-A) (TSH, follicle-stimulating hormone, alpha-subunit and thyroglobulin) lectin affinity chromatography measurement. RESULTS: CDT concentrations were very high in the two patients with CDG-I and moderately enhanced in the remaining two. In the two CDG-I patients, Ricin analysis of immunopurified TSH showed a severe impairment of lectin binding, both before and after neuroaminidase treatment, indicating a nearly complete lack of terminal sialic acid and galactose residues. In these two cases, Con-A analysis showed a significant prevalence of firmly bound isoforms with poorly processed carbohydrate chains. In the remaining two cases with unknown CDG classification, TSH binding pattern to Ricin was modestly affected and Con-A analysis showed the prevalence of weakly bound glycoprotein isoforms. CONCLUSIONS: The results of Ricin analyses in all four patients were consistent with the CDT test and/or serum transferrin IEF. The severe alteration of TSH binding pattern to Ricin seems to be characteristic of CDG-I. Nevertheless, TSH biological properties are not severely altered, as normal thyroid function was found in both cases.
The decrease of IGF-I, IGF-binding protein-3 and bone alkaline phosphatase isoforms during gluten challenge correlates with small intestinal inflammation in children with coeliac disease
Authors: Jansson UH , Kristiansson B , Magnusson P , Larsson L , Albertsson-Wikland K , Bjarnason R
Published: January 2005

OBJECTIVE: In children with coeliac disease, the ingestion of gluten causes small intestinal inflammation and a clinical picture of malabsorption, weight reduction and short stature. Decreased alkaline phosphatase (ALP) during gluten challenge was found in a previous study. ALP is a marker of bone formation and ALP activities are correlated with growth velocity. The aim of this study was to characterise the previously observed decrease of total ALP by investigating three specific bone ALP isoforms (bone/intestinal, B1 and B2) and three specific liver ALP isoforms (L1, L2 and L3) and, moreover, to correlate these ALP isoforms with other growth factors and growth markers. In addition, we also studied the association with possible weight changes, small intestinal mucosa inflammation, sex, age and gluten dose during gluten challenge. MATERIALS AND METHODS: Bone and liver ALP isoforms, IGF-I, IGF-binding protein (IGFBP)-3 and serum cross-linked carboxy-terminal telopeptide of type I collagen (ICTP) were measured together with change in weight and small intestinal mucosa histopathology in 54 children with earlier enteropathy who participated in a 4-week gluten challenge. RESULTS: We observed a decreased total ALP activity after 4 weeks of gluten challenge, 7.8+/-1.8 to 6.5+/-1.7 microkat/l (means +/- s.d.), which was mainly due to a reduction of the bone ALP isoforms. The sum of all three bone ALP isoforms decreased from 6.3+/-1.7 to 5.1+/-1.6 microkat/l. The decreased activities of the bone ALP isoforms correlated with the observed reductions of IGF-I (r=0.74, P<0.001), IGFBP-3 (r=0.51, P<0.001) and ICTP (r=0.57, P<0.001). The decrease of the growth factors and growth markers correlated with weight reduction, but when influences from the change in weight were adjusted for, the partial correlation of the small intestinal mucosa inflammation was significant for IGF-I (r=-0.56, P<0.001) and IGFBP-3 (r=-0.55, P<0.001). CONCLUSION: The decrease of total ALP was due to a reduction of bone ALP. The decrease of IGF-I and IGFBP-3 was independently correlated with weight change and small intestinal inflammation.