bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of the novel adipocyte-derived hormone adiponectin in human disease
Authors: Diez JJ , Iglesias P
Published: January 2005

Adiponectin, also called GBP-28, apM1, AdipoQ and Acrp30, is a novel adipose tIssue-specific protein that has structural homology to collagen VIII and X and complement factor C1q, and that circulates in human plasma at high levels. It is one of the physiologically active polypeptides secreted by adipose tIssue, whose multiple functions have started to be understood in the last few Years.A reduction in adiponectin expression is associated with insulin resistance in some animal models. Administration of adiponectin has been accompanied by a reduction in plasma glucose and an increase in insulin sensitivity. In addition, thiazolidinediones, drugs that enhance insulin sensitivity through stimulation of the peroxisome proliferator-activated receptor-gamma, increase plasma adiponectin and mRNA levels in mice. On the other hand, this adipocyte protein seems to play a protective role in experimental models of vascular injury. In humans, adiponectin levels are inversely related to the degree of adiposity and positively associated with insulin sensitivity both in healthy subjects and in diabetic patients. Plasma adiponectin levels have been reported to be decreased in some insulin-resistant states, such as obesity and type 2 diabetes mellitus, and also in patients with coronary artery disease. On the contrary, chronic renal failure, type 1 diabetes and anorexia nervosa are associated with increased plasma adiponectin levels. Concentrations of plasma adiponectin have been shown to correlate negatively with glucose, insulin, triglyceride levels and body mass index, and positively with high-density lipoprotein-cholesterol levels and insulin-stimulated glucose disposal. Weight loss and therapy with thiazolidinediones increased endogenous adiponectin production in humans.Adiponectin increases insulin sensitivity by increasing tIssue fat oxidation, resulting in reduced circulating fatty acid levels and reduced intracellular triglyceride contents in liver and muscle. This protein also suppresses the expression of adhesion molecules in vascular endothelial cells and cytokine production from macrophages, thus inhibiting the inflammatory processes that occur during the early phases of atherosclerosis. In view of these data, it is possible that hypoadiponectinemia may play a role in the development of atherosclerotic vascular disease.In summary, the ability of adiponectin to increase insulin sensitivity in conjunction with its anti-inflammatory and anti-atherogenic properties have made this novel adipocytokine a promising therapeutic tool for the future, with potential applications in states associated with low plasma adiponectin levels.
The prevalence of anti-thyroid peroxidase antibodies and autoimmune thyroiditis in children and adolescents in an iodine replete area
Authors: Kabelitz M , Liesenkotter KP , Stach B , Willgerodt H , Stablein W , Singendonk W , Jager-Roman E , Litzenborger H , Ehnert B , Gruters A
Published: January 2005

BACKGROUND: The iodine supply of the population in Berlin has normalized during the last 5 Years. Therefore autoimmune thyroiditis has become the most important differential diagnosis in children and adolescents with goiter. OBJECTIVE: The aim of the present study was to define the prevalence of anti-thyroid peroxidase (TPO) antibodies and autoimmune thyroiditis in children and adolescents with a normalized iodine intake. DESIGN: To enable the measurement of antibodies to thyroid peroxidase (anti-TPO-Ab) in a large cohort, a method to determine anti-TPO-Ab in dried filter paper blood spots was established. In co-operation with pediatricians the antibody prevalence was assessed and data regarding thyroid size, echostructure and the medical history concerning iodine intake and familial thyroid diseases were collected. METHODS: 660 children and adolescents participated in the study; urinary iodine, TSH and TPO-Ab were measured and an ultrasound of the thyroid gland was performed. RESULTS: The sensitivity of the newly established filter paper assay was 91.8% and specificity was 100%. The results confirmed the improved iodine supply, with a median urinary iodine concentration of 139 microg iodine/g creatinine. The prevalence of anti-TPO-Ab was 3.4% with a female to male ratio of 2.7:1. CONCLUSION: The prevalence of anti-TPO-Ab is lower or equal to data reported from other iodine sufficient areas. Data from a moderate iodine deficiency in schoolchildren range from 0.0 to 7.3%. Using the new filter paper method field studies can be implemented to monitor the effect of changes in iodine nutrition on thyroid autoimmunity. Furthermore, this study on the prevalence of anti-TPO-Ab in a cohort of healthy children and adolescents in an iodine replete area can serve as reference data for future investigations and for the comparison with other groups of patients with increased risks for thyroid autoimmunity.
Hypercalcemia due to sun exposure in a patient with multiple myeloma and elevated parathyroid hormone-related protein
Authors: Papapetrou PD , Bergi-Stamatelou M , Karga H , Thanou S
Published: January 2005

A patient with multiple myeloma who developed hypercalcemia during three different stages of his disease, with a different hypercalcemic agent elevated in his serum on each occasion, is described. The initial episode of hypercalcemia was associated with high serum interleukin-6 (IL-6). After treatment for myeloma normocalcemia was achieved. Subsequently, a relapse of hypercalcemia occurred, this time characterized by frankly elevated plasma parathyroid hormone-related protein (PTHrP) but normal IL-6. Monotherapy with pamidronate infusions resulted in remission of the hypercalcemia and a significant fall in PTHrP levels. A third spell of hypercalcemia characterized by an acute rise in serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D to abnormally high levels occurred during the summer season after prolonged and intense exposure to the sun.
Pharyngeal pituitary non-functioning adenoma with normal intra-sellar gland: massive tumor shrinkage on octreotide therapy
Authors: Pugnale N , Waridel F , Bouzourene H , Boubaker A , Pugnale M , Gaillard RC , Gomez F
Published: January 2005

OBJECTIVE: Functioning or non-functioning ectopic tumors may develop from pharyngeal pituitary remnants. They constitute <1% of all obstructive pharyngeal masses and they have a strong tendency to bleed. We report a case of a non-functioning ectopic pituitary adenoma of the rhino-pharynx studied over a long-term somatostatin analog treatment. PATIENT AND TREATMENT: A 60-Year-old woman presented with severe posterior epistaxis. She had complained of nasal obstruction for the past 2 Years. Magnetic resonance imaging (MRI) and endoscopic examination revealed a 2 cm exophytic, bleeding mass in the cavum, which was judged inoperable, and a biopsy was performed. On immunostaining, tumor cells were positive for pancytokeratins MNF 116 and C11, epithelial membrane antigen, chromogranin and neuron-specific enolase (NSE), and negative for synaptophysin, desmin, actin, estrogen and progesterone receptors, all anterior pituitary hormones and human chorionic gonadotropin. Blood levels of the above hormones and tumor markers were normal, except for a moderate elevation of NSE (33.8 microg/l, normal value <12 microg/l). It was concluded that this was a non-functioning pituitary adenoma of the rhino-pharynx. MRI showed a normal intra-sellar pituitary gland, including the normal bright signal of the posterior lobe. Somatostatin receptor scintigraphy (SRS) disclosed intense tracer uptake in the tumor, indicating high somatostatin receptor content. There was also an intense uptake in the intra-sellar pituitary. Therapy with long-acting octreotide was started, 20 mg per Month i.m. RESULTS: The patient has been on octreotide for the last 12 Months. Nasal obstruction rapidly subsided and bleeding did not recur. Repeated endoscopic examinations showed rapid tumor reduction, the mass shrinkage being almost complete at 3 Months. This was confirmed by MRI, while SRS showed markedly decreased uptake in the residual tumor and the intra-sellar pituitary, and NSE became normal. CONCLUSION: Pharyngeal pituitary remnant adenomas are rare, but they must be considered in the differential diagnosis of bleeding or obstructive masses of the rhino-pharynx. In this case, the positive SRS influenced the choice of octreotide, as an alternative to surgery. As we show for the first time in this location, octreotide can exert prolonged and marked anti-tumoral effects in non-functioning adenoma.
Retinoic acid for redifferentiation of thyroid cancer--does it hold its promise?
Authors: Gruning T , Tiepolt C , Zophel K , Bredow J , Kropp J , Franke WG
Published: January 2005

OBJECTIVES: To evaluate the effectiveness of isotretinoin for improving (131)I uptake in recurrent/metastasized thyroid cancer with no/insufficient (131)I uptake. DESIGN: Retrospective analysis of 25 patients treated between June 1999 and May 2001. METHODS: 15 female and 10 male patients were given isotretinoin at 1 mg/kg for 3 months, followed by (131)I treatment. All patients received a (131)I scan 72 h after administration, thyroglobulin measurement, chest X-ray and ultrasound of the neck, and some patients underwent a (18)F-fluorodeoxyglucose (FDG) positron emission tomography (n=14) and computed tomography scan of the chest (n=11). RESULTS: In two out of 14 patients with raised thyroglobulin but no (131)I uptake, a slightly improved (131)I uptake was seen. In a further 11 patients an improvement of (131)I uptake of known lesions was desired or further non-(131)I-accumulating lesions were known. A dosimetrically relevant improvement of uptake was seen in three of these patients. (18)F-FDG uptake and thyroglobulin did not correlate with the success/failure of the isotretinoin treatment. Side effects including a strong "sunburn", cheilitis, mucositis, conjunctivitis and raised transaminases occurred in two-thirds of patients. They were of an overall tolerable level and were reversible after isotretinoin had been stopped. CONCLUSION: From our clinical experience over a period of 2 years we conclude that the therapeutic effect of isotretinoin in thyroid cancer is certainly less than previously reported. An indiscriminate use of isotretinoin in all patients with otherwise untreatable thyroid cancer cannot be recommended.
Decrease in vitamin D receptor and calcium-sensing receptor in highly proliferative parathyroid adenomas
Authors: Yano S , Sugimoto T , Tsukamoto T , Chihara K , Kobayashi A , Kitazawa S , Maeda S , Kitazawa R
Published: January 2005

OBJECTIVE: A significant decrease in vitamin D receptor (VDR) and calcium-sensing receptor (CaSR) protein expression has been demonstrated recently in parathyroid (PT) adenomas. In this study, we investigated the relationships between the proliferative activity of parathyroid glands (PTGs) and the expression of VDR as well as CaSR, and compared it with the clinical severity in patients with primary hyperparathyroidism (1 degrees HPT). DESIGN: Seven patients with 1 degrees HPT were included in this study. Four patients with thyroid carcinoma served as controls. METHODS: Immunohistochemical staining was performed on serial sections of PTGs with specific antibodies against CaSR, VDR, and Ki67. Areas examined in each section were selected at random in relation to the gland size. The number of Ki67-positive cells was expressed as a labeling index (LI; positive cells per 1000 PT cells). The expression of CaSR and VDR was semi-quantitatively analyzed based on the intensity of staining. After averages of the scores from all areas were calculated, CaSR and VDR scores, and Ki67 LI were assigned to each gland for use in statistical analyses. RESULTS: In PT adenomas, scores of VDR and CaSR were markedly lower than in normal PTGs (P<0.01), while the proportion of Ki67-positive cells in PT adenomas was significantly higher than in normal PTGs (P<0.01). Single regression analyses revealed that Ki67 LI was positively correlated with serum levels of intact parathyroid hormone and Ca, and PTG weight (R=0.70, P<0.05, R=0.78, P<0.01 and R=0.84, P<0.05 respectively). Ki67 LI was negatively correlated with CaSR and VDR scores (R=-0.78, P<0.01 and R=-0.72, P<0.05 respectively). Moreover, there was a strong positive relationship between CaSR and VDR expression (R=0.95, P<0.001). CONCLUSIONS: Marked decreases in VDR and CaSR expression could, at least in part, be responsible for the high proliferation of PT cells and the pathological progression of 1 degree HPT.
Helicobacter pylori has no effect on plasma ghrelin levels
Authors: Gokcel A , Gumurdulu Y , Kayaselcuk F , Serin E , Ozer B , Ozsahin AK , Guvener N
Published: January 2005

OBJECTIVE: Helicobacter pylori is the major etiologic agent for chronic active gastritis, and it also plays a crucial role in gastric and duodenal ulcer disease, as well as in gastric carcinoma. H. pylori infection has been shown to decrease plasma somatostatin (SST) and increase plasma gastrin concentrations. Ghrelin is a recently discovered peptide produced mostly in the stomach of rodents and humans and is secreted into the bloodstream. There is no data in the literature about the relationship between H. pylori and ghrelin. DESIGN: Thirty-nine age- and BMI-matched H. pylori infection positive and negative women, from whom biopsy specimens were taken during gastric endoscopy, were included in the study. METHODS: Total ghrelin was measured by enzyme immunoassay (EIA) in Medistek. All samples were measured in duplicate and averaged; results differing by more than 20% were re-assayed. Two biopsy specimens from antrum, corpus and fundus were obtained. RESULTS: Fifteen of the subjects were H. pylori negative and 24 were H. pylori positive. Age, BMI, lipid profile and insulin sensitivity indices of the groups were similar. Plasma ghrelin levels (375.92+/-7.10 vs 370.00+/-4.14 pmol/l; P>0.05) of H. pylori negative and positive groups did not differ significantly. CONCLUSION: H. pylori has no effect on plasma ghrelin concentration.
Magnetic resonance imaging study of pituitary morphology in subjects homozygous and heterozygous for a null mutation of the GHRH receptor gene
Authors: Oliveira HA , Salvatori R , Krauss MP , Oliveira CR , Silva PR , Aguiar-Oliveira MH
Published: January 2005

OBJECTIVE: Somatotrophs represent the majority of cells in the anterior pituitary, and their numeric reduction can cause anterior pituitary hypoplasia (APH). Small numbers of patients with familial isolated GH deficiency (IGHD) due to bi-allelic mutations in the GHRH receptor (GHRHR) gene (GHRHR) have been reported to have APH. We tested if APH was present in a large cohort of patients homozygous and heterozygous for a GHRHR mutation. DESIGN: We studied pituitary morphology in adult and pediatric age subjects (8 years of age and older) belonging to a large extended Brazilian kindred with a high prevalence of IGHD due to a null GHRHR mutation. METHODS: We performed brain magnetic resonance imaging (MRI) in 38 subjects, divided into four groups: group I: normal adults (five males, four females, age 38+/-11.7 years); group II: heterozygous adults (six males, seven females, age 42.23+/-8.8 years); group III: homozygous GH-naive affected adults (three males, five females, age 41.4+/-15.0 years); group IV: homozygous affected children (three males, five females, age 11.9+/-2.5 years). Results are expressed as means+/-s.d. RESULTS: Pituitary height (mm) was not different between groups II and I (4.61+/-1.55 and 4.41+/-0.62 respectively), but it was significantly reduced in groups III (2.67+/-0.87, P<0.001) and IV (2.87+/-0.79, P<0.001) compared with group I. Pituitary volume (mm(3)) was normal in group II (417.12+/-140.86), but it was significantly reduced in groups III and IV (124.06+/-64.27 and 155.68+/-39.79 respectively vs 414.56+/-71.57; both P<0.001). The volume ratio (calculated by multiplying the pituitary volume by 1000 and dividing it by cranial volume) was significantly lower in the affected subjects (groups III and IV) (0.06+/-0.02) than in unaffected (groups I and II) (0.15+/-0.04; P<0.0001), demonstrating that APH is not due to reduction of cranial volume. CONCLUSIONS: APH is present from childhood in patients homozygous for an inactivating GHRHR mutation, but it does not occur in heterozygous subjects. In our cohort, the presence of normal anterior pituitary size by MRI rules out homozygosity for a GHRHR mutation in subjects who are 8 years of age or older.
Major hyperestrogenism in a feminizing adrenocortical adenoma despite a moderate overexpression of the aromatase enzyme
Authors: Bouraima H , Lireux B , Mittre H , Benhaim A , Herrou M , Mahoudeau J , Guillon-Metz F , Kottler ML , Reznik Y
Published: January 2005

A 30-year-old male was referred for the rapid development of gynecomastia, and dramatic hyperestrogenemia was assessed: plasma estrone, estradiol but also cortisol were not suppressed by high-dose dexamethasone, while gonadotropin pulsatility was completely abolished. A 60-mm right adrenal tumor was evidenced on computed tomography-scan, and the patient underwent adrenalectomy. The tumor was found to express a moderate increase in aromatase activity compared with adjacent non-neoplastic adrenal tissue. Quantitative RT-PCR also showed a weak and non-significant increase in total aromatase mRNA in the tumor compared with normal adrenal tissue. Aromatase transcripts were mainly promoter PII-derived, but different patterns of aromatase minor transcripts were found: promoter I.3- and I.6-derived transcripts were identified in the tumor, while only promoter I.4-derived transcripts were found in normal adrenal. This case report demonstrates that a sharp aromatase overexpression is not a prerequisite for clinical and biochemical hyperestrogenism, and further characterizes the aromatase promoter utilization in this feminizing adrenocortical tumor and in the normal adrenal cortex.
Regulation of CYP19 gene expression in primary human osteoblasts: effects of vitamin D and other treatments
Authors: Enjuanes A , Garcia-Giralt N , Supervia A , Nogues X , Mellibovsky L , Carbonell J , Grinberg D , Balcells S , Diez-Perez A
Published: January 2005

OBJECTIVE: Extragonadal estrogen biosynthesis is relevant for the regulation of bone metabolism. The aims of this paper were: (i) to examine CYP19 (aromatase) gene expression in primary cultures of osteoblasts under several hormone and cytokine treatments and (ii) to study the promoter usage of CYP19 in these cells. METHODS: Primary cultures of osteoblasts were obtained from healthy donors. The effects of vitamin D and other factors on CYP19 expression were analysed by semiquantitative RT-PCR. Furthermore, CYP19 alternative promoter usage under the different treatments was characterized by RT-PCR. RESULTS: CYP19 transcripts were detected in cultured human osteoblasts in serum-free conditions. Vitamin D, dexamethasone, 17beta-estradiol and testosterone increased transcript levels of CYP19, whereas interleukin-1beta or tumor necrosis factor alpha decreased them. Aromatase mRNA produced under treatment with vitamin D was transcribed from promoters I.4 and I.3, while stimulation with dexamethasone or dexamethasone plus vitamin D also involved promoter I.2. Testosterone activated promoters I.2 and I.4. CONCLUSIONS: Our results suggested that vitamin D, testosterone, estrogens and glucocorticoids regulate CYP19 gene expression in human primary osteoblasts and the main promoter used appears to be promoter I.4. Promoters pII and I.3 seem to be related to basal transcription and may mediate estrogen stimulation, while promoter I.2 seems to play a role in the effect of glucocorticoids. These findings indicate that vitamin D and several hormones regulate local estrogen synthesis in human osteoblasts mainly through usage of promoters I.4 and I.3.
Pitfalls in endosonographic imaging of suspected insulinomas: pancreatic nodules of unknown dignity
Authors: Kann PH , Wirkus B , Keth A , Goitom K
Published: January 2005

OBJECTIVE: Endosonography enables localization and characterization of gastroenteropancreatic neuroendocrine tumors. We have studied the problem of misleading abnormalities of pancreatic morphology as obtained by endosonographic imaging. DESIGN AND METHODS: A total of 438 endosonographies performed for known or suspected diseases of the adrenal glands and/or the pancreas and/or suspected metastases in the neighboring tissues were analyzed. RESULTS: In the pancreas, nine benign insulinomas, four non-metastatic islet cell carcinomas, and multiple benign neuroendocrine tumors in one patient with multiple-endocrine neoplasia-1 (MEN-1) disease were detected and correctly localized as proven by postoperative histology. In three further patients with genetic diagnosis of MEN-1, asymptomatic tumors were detected and are under observation. However, we also found an 8 x 4 mm hypoechoic tumor in the cauda pancreatis of a patient with severe factitial hypoglycemia (glimepiride). In another patient suffering from severe hypoglycemia, a hypoechoic area of 24 x 10 mm in the processus uncinatus/caput pancreatis was found. Although organic hyperinsulinism was excluded, this patient underwent surgery because of suspected pancreatic carcinoma. There was normal pancreatic tissue in the abnormal region, which was also localized by intraoperative sonography. In a third patient with an adrenal carcinoma, a 6 x 3 mm hypoechoic nodule in the cauda pancreatis did not change its morphology over an observation period of 13 months, its clinical relevance is completely unclear. CONCLUSIONS: Pancreatic nodules of unknown dignity were detected in nearly 1% of our patients and must be considered to be a diagnostic problem. These experiences clearly show, on the one hand, that pancreatic endosonography is a very useful diagnostic support in the management of endocrine tumor patients. However, on the other hand, endosonography of endocrine organs is not a substitute for careful endocrinological examination and testing and must be considered in the context of endocrinological findings.
Association between measures of insulin sensitivity and circulating levels of interleukin-8, interleukin-6 and tumor necrosis factor-alpha. Effect of weight loss in obese men
Authors: Bruun JM , Verdich C , Toubro S , Astrup A , Richelsen B
Published: January 2005

OBJECTIVE: To study the association between anthropometric and metabolic parameters as well as the effect of weight loss on plasma levels of the adipose tissue-derived cytokines interleukin-8 (IL-8), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in abdominal obese men. SUBJECTS: Nineteen obese (mean body mass index (BMI): 38.6+/-0.6 kg/m(2)) and ten lean men (mean BMI: 23.4+/-0.4 kg/m(2)) were included in the study. The obese subjects received a 4.2 MJ/day diet for 8 weeks, followed by 8 weeks on energy restriction (6.2 MJ/day) and 8 weeks on a weight-maintenance diet. MEASUREMENTS: A dual energy X-ray absorptiometry (DEXA)-scan was performed to estimate body composition. Plasma levels of IL-8, IL-6 and TNF-alpha were measured by a specific ELISA method. Insulin sensitivity was assessed by the homeostasis model assessment method (HOMA). RESULTS: Plasma levels of IL-8 and IL-6 were 30-40% higher in obese as compared with lean subjects (P<0.05), whereas no group difference in TNF-alpha was observed. During the intervention, obese subjects obtained a 30% reduction in fat mass (P<0.001), fasting insulin (P<0.05) and HOMA (P<0.05). Plasma levels of TNF-alpha and IL-6 were decreased by 25-30% (P<0.001) but IL-8 was increased by 30% (P<0.001) after weight loss. IL-8 and IL-6 were correlated with measures of insulin resistance, and changes in IL-6 but not IL-8 were correlated with the improvement in insulin sensitivity after weight loss. CONCLUSION: Plasma levels of IL-8 and IL-6 were found to be increased and were correlated with measures of insulin resistance in abdominal obese male subjects. Weight loss was associated with changes in the circulating levels of IL-8, IL-6 and TNF-alpha indicating that these cytokines are influenced by weight loss.
Reduced expression of uncoupling proteins-2 and -3 in adipose tissue in post-obese patients submitted to biliopancreatic diversion
Authors: Vettor R , Mingrone G , Manco M , Granzotto M , Milan G , Scarda A , Lombardi A , Greco AV , Federspil G
Published: January 2005

OBJECTIVE: Little is known about the physiological role and the regulation of uncoupling proteins-2 and -3 (UCP-2 and -3) in adipose tissue. We investigated whether the expression of UCP-2 and -3 in adipose tissue was affected by weight loss due to a biliopancreatic diversion (BPD) and related to the daily energy expenditure (24-h EE). DESIGN: Ten morbidly obese subjects (mean body mass index +/- s.e.m.=49.80 +/- 2.51 kg/m(2)) were studied before and 18+/-2 Months after BPD. METHODS: We determined body composition using tritiated water and 24-h EE in a respiratory chamber. Adipose tissue UCP-2 and -3 mRNA, plasma insulin, glucose, free fatty acids (NEFA), free triiodothyronine (FT3), free thyroxine (FT4) and leptin were assayed before and after BPD. RESULTS: BPD treatment resulted in a marked weight loss (P<0.001) mainly due to a fat mass reduction. A significant decrease in 24-h EE/fat-free mass (FFM) (P<0.05) and in UCP-2 (P<0.05) and UCP-3 (P<0.05) mRNA was observed. A significant reduction in plasma insulin, glucose, NEFA, FT3, FT4 and leptin was seen after BPD. The decline in plasma leptin and FFA was tightly correlated with the decrease in both UCP-2 and -3. A significant correlation was found between changes in FT3 and variations in 24-h EE (r=0.64, P<0.05). In a multiple-regression analysis changes in 24-h EE/FFM after BPD were significantly correlated with changes in UCP-3 expression (P<0.05). CONCLUSION: These findings suggest that UCPs in adipose tissue may play a role in the reduction in 24-h EE observed in post-obese individuals.
Expression of cAMP response element-binding protein and sodium iodide symporter in benign non-functioning and malignant thyroid tumours
Authors: Luciani P , Buci L , Conforti B , Tonacchera M , Agretti P , Elisei R , Vivaldi A , Cioppi F , Biliotti G , Manca G , Vitti P , Serio M , Peri A
Published: January 2005

OBJECTIVE: Reduced expression or defective targeting of the sodium/iodide symporter (NIS) to the cell membrane in thyroid tumours has been reported. The expression of the NIS gene is up-regulated by TSH through the cAMP pathway and the characterization of the promoter region of the rat NIS gene revealed the existence of a degenerate cAMP response element (CRE) sequence. The cAMP-dependent transcription factor cAMP response element-binding protein (CREB) binds to CRE acting, upon phosphorylation, as a transcriptional activator. In this study we evaluated the expression of CREB and NIS gene in thyroid non-functioning adenomas (n=18) and carcinomas (n=20), as well as in the corresponding normal tissue. METHODS: The levels of CREB and NIS mRNA were determined by quantitative real-time RT-PCR, whereas CREB protein (total and phosphorylated) was analyzed by Western blot. RESULTS: The levels of CREB mRNA in thyroid carcinomas, but not in adenomas, were significantly lower than in the corresponding normal tissue (4.63+/-0.89 vs 9.51+/-2.01 pg/microg total RNA, means+/-s.e., P=0.025). CREB protein levels, which were determined in a subset of samples, were in quite good agreement with mRNA data. NIS mRNA levels did not differ in adenomas or carcinomas, compared with the corresponding normal tissue and no significant relationship with the levels of CREB mRNA was observed. CONCLUSIONS: Our results have indicated for the first time that reduced levels of CREB expression are a feature of thyroid carcinomas, and confirm that different factors are likely to modulate NIS expression.
Outcome in patients with differentiated thyroid cancer with negative diagnostic whole-body scanning and detectable stimulated thyroglobulin
Authors: van Tol KM , Jager PL , de Vries EG , Piers DA , Boezen HM , Sluiter WJ , Dullaart RP , Links TP
Published: January 2005

BACKGROUND: Management of patients with differentiated thyroid carcinoma with negative diagnostic radioiodide scanning and increased serum thyroglobulin (Tg) concentrations is a widely debated problem. High-dose iodine-131 treatment of patients who have a negative (131)I diagnostic whole-body scan (WBS) is advocated. However, the therapeutic benefit of this "blind" treatment is not clear. OBJECTIVE: To investigate the course of serum Tg during thyroid hormone suppression therapy (Tg-on) and clinical outcome in patients with negative diagnostic (131)I scanning and increased serum Tg concentrations during thyroid hormone withdrawal (Tg-off), after treatment with high-dose (131)I. DESIGN: Retrospective single-center study. METHODS: Fifty-six patients were treated with a blind therapeutic dose of 150 mCi (131)I. Median follow-up from this treatment until the end of observation was 4.2 Years (range 0.5-13.5 Years). RESULTS: The post-treatment WBS revealed (131)I uptake in 28 patients, but none in the remaining 28 patients. In this study the Tg-on values did not change after treatment in either the positive or the negative post-treatment WBS group. During follow-up, 18 of the 28 patients with a positive post-treatment WBS achieved complete remission, compared with 10 of the 28 patients with a negative post-treatment WBS. Nine patients in the negative group died, but no patients died in the positive post-treatment group (P=0.001). CONCLUSIONS: High-dose iodine treatment in diagnostically negative patients who have a negative post-treatment scan seems to confer no additional value for tumor reduction and survival. In patients with a positive post-treatment scan, high-dose iodine treatment can be used as a diagnostic tool to identify tumor location, and a therapeutic effect may be present in individual cases.
Influence of renal function on clinico-pathological features of primary hyperparathyroidism
Authors: Yamashita H , Noguchi S , Uchino S , Watanabe S , Murakami T , Ogawa T , Masatsugu T , Takamatsu Y , Miyatake E , Yamashita H
Published: January 2005

OBJECTIVE: Disturbed renal function may play an important role in the clinico-pathological presentation of primary hyperparathyroidism (pHPT). We studied the influence of renal function on the clinico-pathological characteristics of 141 patients (123 women and 18 men) with surgically proven pHPT. METHODS: The 141 patients were assigned to one of two groups based on creatinine clearance (C(cr)) level: a renal insufficiency group (n=37) in which C(cr) of patients was <70 ml/min and a normal renal function group (n=104) in which C(cr) was > or =70 ml/min. Clinical presentation and biochemical indices were evaluated and compared between the two groups. RESULTS: Age, and frequency of hypertension and of diabetes mellitus were significantly (P<0.001, P<0.05 and P<0.05 respectively) higher in the renal insufficiency group than in the normal renal function group. Serum levels of calcium, intact parathyroid hormone and bone Gla protein were significantly (P<0.05) higher and the excised parathyroid weighed significantly more (P<0.05) in the renal insufficiency group than in the normal renal function group; however, serum 1,25-dihydroxyvitamin D (1,25(OH)(2)D) and 24 h urinary calcium excretion were significantly (P<0.001 and P<0.05 respectively) lower in the former than in the latter group. There was a significant inverse correlation between C(cr) level and serum calcium (r=0.315, P<0.001) and a significant positive correlation between C(cr) level, 1,25(OH)(2)D (r=0.315, P<0.001), and 24 h calcium excretion (r=0.458, P<0.0001). CONCLUSIONS: Clinico-pathological features of pHPT were notably influenced by even moderate renal insufficiency. Urinary calcium excretion decreased according to the decrease in glomerular filtration rate. Therefore, endocrinologists need to appraise urinary calcium excretion and renal function of pHPT patients when considering surgery or in discriminating familial hypocalciuric hypercalcemia.
Severe hyponatremia due to hypopituitarism with adrenal insufficiency: report on 28 cases
Authors: Diederich S , Franzen NF , Bahr V , Oelkers W
Published: January 2005

OBJECTIVE: Severe hyponatremia due to hypopituitarism and adrenal insufficiency can be life-threatening, and treatment with glucocorticoids is very effective once the diagnosis of the underlying disorder has been made. In our experience, the diagnosis of hypopituitarism in hyponatremic patients is often overlooked. METHODS: In a retrospective study we screened the files of 185 patients with severe hyponatremia (<130 mmol/l) that had been seen in one endocrinological unit of a university hospital between 1981 and 2001 in order to describe the clinical spectrum of patients with hyponatremia and hypopituitarism including secondary adrenal insufficiency. RESULTS: In 139 cases it was possible to clearly ascribe the patients to the pathophysiological groups of (i) primary sodium deficiency, (ii) edematous disorders, and (iii) normovolemic disorders including the "syndrome of inappropriate secretion of antidiuretic hormone" (SIADH). Twenty-eight patients with severe "normovolemic hyponatremia" (serum sodium: 116+/-7 mmol/l, mean+/-s.d.) had hypopituitarism and secondary adrenal insufficiency as shown by basal cortisol measurements and dynamic tests of adrenal function. In 25 cases of this group hypopituitarism (mostly due to empty sella, Sheehan's syndrome and pituitary tumors) had not been recognized previously, and in 12 cases recurrent hyponatremia during previous hospital admissions (up to four times) could be documented. The mean age of these patients (21 women, seven men) was 68 Years. The most frequently occurring clinical signs were missing or scanty pubic and axillary hair, pale and doughy skin, and small testicles in the men. Frequent symptoms like nausea and vomiting, confusion, disorientation, somnolence or coma were similar to those in 91 patients with SIADH. Basal serum cortisol levels in the acutely ill state ranged from 20 to 439 nmol/l (mean+/-s.d.: 157+/-123), while in 30 other severely hyponatremic patients it ranged from 274 to 1732 nmol/l (732+/-351 nmol/l). In most patients with hyponatremic hypopituitarism, plasma antidiuretic hormone levels were inappropriately high, probably due to a failure of endogenous cortisol to suppress the hormone in a stressful situation. All patients recovered after low-dose hydrocortisone substitution. Most patients had other pituitary hormone deficiencies and were appropriately substituted subsequently. CONCLUSIONS: Hypopituitarism including secondary adrenal insufficiency seems to be a frequently overlooked cause of severe hyponatremia. A high level of suspicion is the best way to recognize the underlying disorder. Treatment with hydrocortisone is very effective.
The R271W mutant form of Pit-1 does not act as a dominant inhibitor of Pit-1 action to activate the promoters of GH and prolactin genes
Authors: Kishimoto M , Okimura Y , Fumoto M , Iguchi G , Iida K , Kaji H , Chihara K
Published: January 2005

OBJECTIVE: Genetic abnormalities of the pituitary specific transcription factor, Pit-1, have been reported in several patients with GH, prolactin (PRL) and TSH deficiencies. The most common is a mutation altering an arginine to a tryptophan in codon 271 (R271W) in one allele of the Pit-1 gene. According to the previous in vitro expression study, R271W acted as a dominant negative inhibitor of the wild type to activate the GH promoter. However, healthy carriers with this mutation, who should be affected by the dominant negative effect of R271W, have also been reported. The aim of this study was to clarify in more detail the function of this mutant form of Pit-1. METHODS: Transcriptional activity of R271W for the expression of Pit-1-associated genes was investigated in COS7 cells with the aid of transient transfection assays. The 1.8 kb rat GH, 0.6 kb rat PRL or 1.9 kb rat PRL 5'-flanking regions were inserted upstream of the luciferase reporter gene and were used for functional analysis of R271W. Another reporter gene containing seven Pit-1 responsive elements was also used. The same experiments were also performed using JEG3 and CHO cells. RESULTS: We could not confirm the dominant negative effect of R271W on wild type Pit-1. Furthermore, our expression study revealed that R271W could activate the promoters of GH and PRL genes to levels similar to the wild type. CONCLUSION: Taken together with the evidence that phenotypically normal cases have been reported with this mutation, our results deny the relationship between R271W and combined pituitary hormone deficiency.
Adrenal function during coronary artery bypass grafting
Authors: Henzen C , Kobza R , Schwaller-Protzmann B , Stulz P , Briner VA
Published: January 2005

OBJECTIVE: To assess adrenal function in patients undergoing coronary artery bypass grafting (CABG) by means of the low-dose (1 microg) ACTH test, and to correlate the adrenal function with clinical outcome. METHODS: During a 5-Month period we prospectively included 45 patients undergoing elective CABG with cardiopulmonary bypass and without symptoms of endocrine disease. Low-dose (1 microg) ACTH tests were performed on the day before surgery (day -1), immediately after the operation (day 0), on the two subsequent days in the intensive care unit (day 1 and day 2), and on the day of discharge from the hospital. A number of clinical, hemodynamic and laboratory parameters were monitored throughout. RESULTS: On day -1, 75% of the study patients had normal stimulated plasma cortisol concentrations. Eleven patients (25%) had an impaired adrenal response to 1 microg ACTH. The stimulated plasma cortisol concentrations in patients who had an inadequate adrenal response on day -1 remained significantly reduced on day 1 (756+/-205 vs 949+/-259 nmol/l, P=0.03) (mean+/-s.d.), day 2 (644 (580-793) vs 885 (713-1087), P=0.03) (median (interquartile range)), and on the day of discharge (698+/-201 vs 854+/-186, P=0.05). In patients with a normal adrenal response in the preoperative setting peak cortisol concentrations were reached on day 1, in patients with a blunted adrenal response they were reached on day 2. There were significant correlations between the stimulated plasma cortisol concentrations and the blood loss (r=-0.50, P=0.002) and Volume balance (r=0.41, P=0.015). CONCLUSIONS: Occult (partial) adrenal insufficiency is common in patients undergoing CABG who are otherwise asymptomatic as regards endocrine disease. The adrenal function in these patients differs both in the magnitude of cortisol response to ACTH and in the time course, with significantly delayed peak cortisol concentrations. Adequate regulation of Volume balance and the amount of blood loss seem to correlate with adequacy of adrenal function.
Discovery and mechanism of action of pegvisomant
Authors: Kopchick JJ
Published: January 2005

Using a structure-function approach to the understanding of the molecular topology of the GH molecule, we discovered that glycine in the third alpha-helix of GH (G119 of bovine GH and G120 of human GH) was an important amino acid required for GH action. Substitution of this glycine residue with a variety of amino acids results in molecules that lack growth-promoting activity. More importantly, these molecules inhibit the actions of GH both in vitro and in vivo. These results, obtained more than a decade ago, were the basis for the discovery of GH antagonists. Since that time, efforts have been focused on establishing the mechanism by which these antagonists inhibit GH action. In this regard, in vivo expression of GH-antagonist genes in transgenic mice results in dwarf animals. The animals are fertile and possess no abnormal 'phenotypes'. Dwarf mice have also been created by disrupting or 'knocking out' the GH receptor gene. Together, these results have laid the foundation for the clinical use of GH antagonists when endogenous GH levels are increased or when GH is known to be a factor in the progression of the disorder.
Pegvisomant: an advance in clinical efficacy in acromegaly
Authors: Stewart PM
Published: January 2005

Acromegaly is a chronic disorder invariably caused by a growth hormone (GH)-secreting pituitary tumour and is characterised by disabling symptoms (sweating, arthralgia, headache, paraesthesiae, fatigue), significant comorbidities (diabetes mellitus, hypertension, sleep apnoea), and premature mortality. Symptomatic control can be achieved by lowering insulin-like growth factor-I (IGF-I) concentrations to within the age-adjusted normal range, and survival can be improved to match that of the general population. However, even with optimal surgery and current medical therapies (dopamine agonists, somatostatin analogues), 30% to 50% of patients do not achieve target concentrations of IGF-I and GH. Pegvisomant is a new GH-receptor antagonist that blocks GH activity by inhibiting functional dimerisation of GH-receptors. Given as subcutaneous injections at dosages of 10 mg, 15 mg, or 20 mg/day for 3 Months, pegvisomant normalised serum IGF-I concentrations in, respectively, 54%, 81%, and 89% of acromegalic patients. Moreover, long-term pegvisomant therapy normalised IGF-I concentrations in 97% of patients treated for 12 Months or longer, with no evidence of tachyphylaxis. Pegvisomant is the most effective medical therapy, reported to date, in terms of normalisation of circulating IGF-I concentrations. In addition, pegvisomant appears to be safe and well tolerated. Although additional long-term studies are required to further assess safety, the introduction of this innovative treatment should allow for optimal disease control in patients with acromegaly.
Actions of GnRH antagonists on IGF-II, IGF-binding protein-2 and pregnancy-associated plasma protein-A in human granulosa-lutein cells
Authors: Weiss JM , Krautmacher B , Polack S , Diedrich K , Ortmann O
Published: January 2005

OBJECTIVE: Recently, GnRH antagonists (GnRHants) have been introduced for the prevention of premature LH surges during controlled ovarian hyperstimulation (COH). Here we investigated whether the GnRHants cetrorelix and ganirelix exert effects on the human ovarian IGF system. Since controversy exists on the action of GnRH agonists in the human ovary, we also tested the effect of triptorelin on IGF-II, IGF-binding protein-2 (IGFBP-2) and pregnancy-associated plasma protein-A (PAPP-A) in cultured human granulosa-lutein cells. DESIGN: In vitro cell culture study in a research laboratory of a university hospital. PATIENTS: Cells were obtained from patients treated with different protocols of COH. In addition to gonadotropins they received triptorelin or cetrorelix. Cells were treated with triptorelin, cetrorelix or ganirelix, 1 nmol/l each, for 48 h. IGF-II, IGFBP-2 and PAPP-A were measured by RIA and enzyme immunoassay respectively. RESULTS: GnRHants and triptorelin did not affect IGF-II, IGFBP-2 or PAPP-A. CONCLUSIONS: We conclude that GnRHants do not exert any significant effects on the IGF system of granulosa-lutein cells and therefore their introduction into protocols of COH is unlikely to impair ovarian function.
Long-term follow-up of 114 patients with congenital hyperinsulinism
Authors: Meissner T , Wendel U , Burgard P , Schaetzle S , Mayatepek E
Published: January 2005

BACKGROUND: The term congenital hyperinsulinism (CHI) comprises a group of different genetic disorders with the common finding of recurrent episodes of hyperinsulinemic hypoglycemia. OBJECTIVE: To evaluate the clinical presentation, diagnostic criteria, treatment and long-term follow-up in a large cohort of CHI patients. PATIENTS: The data from 114 patients from different hospitals were obtained by a detailed questionnaire. Patients presented neonatally (65%), during infancy (28%) or during childhood (7%). RESULTS: In 20 of 74 (27%) patients with neonatal onset birth weight was greatly increased (group with standard deviation scores (SDS) >2.0) with a mean SDS of 3.2. Twenty-nine percent of neonatal-onset vs 69% of infancy/childhood-onset patients responded to diazoxide and diet or to a carbohydrate-enriched diet alone. Therefore, we observed a high rate of pancreatic surgery performed in the neonatal-onset group (70%) compared with the infancy/childhood-onset group (28%). Partial (3%), subtotal (37%) or near total (15%) pancreatectomy was performed. After pancreatic surgery there appeared a high risk of persistent hypoglycemia (40%). Immediately post-surgery or with a latency of several Years insulin-dependent diabetes mellitus was observed in operated patients (27%). General outcome was poor with a high degree of psychomotor or mental retardation (44%) or epilepsy (25%). An unfavorable outcome correlated with infancy-onset manifestation (chi(2)=6.1, P=0.01). CONCLUSIONS: The high degree of developmental delay, in particular in infancy-onset patients emphasizes the need for a change in treatment strategies to improve the unfavorable outcome. Evaluation of treatment alternatives should take the high risk of developing diabetes mellitus into account.
Proopiomelanocortin, a polypeptide precursor with multiple functions: from physiology to pathological conditions
Authors: Raffin-Sanson ML , de Keyzer Y , Bertagna X
Published: January 2005

Proopiomelanocortin (POMC) is the polypeptide precursor of ACTH. First discovered in anterior pituitary corticotroph cells, it has more recently been revealed to have many other physiological aspects. The fine molecular mechanisms of ACTH biosynthesis show that ACTH is but one piece of a puzzle which contains many other peptides. Present in various tIssues, among which are pituitary, hypothalamus, central nervous system and skin, POMC undergoes extensive post-translational processing. This processing is tIssue-specific and generates, depending on the case, various sets of peptides involved in completely diverse biological functions. POMC expressed in corticotroph cells of the pituitary is necessary for adrenal function. Recent developments have shown that POMC-expressing neurons in the brain play a major role in the control of pain and energy homeostasis. Local production of POMC-derived peptides in skin may influence melanogenesis. A still unknown function in the placenta is likely.POMC has become a paradigmatic polypeptide precursor model illustrating the variable roles of a single gene and its various products in different localities.