bluuebunny/crossref_metadata_2025 huggingface dataset:
Allopregnanolone and dehydroepiandrosterone response to corticotropin-releasing factor in patients suffering from Alzheimer's disease and vascular dementia
Authors: Bernardi F , Lanzone A , Cento RM , Spada RS , Pezzani I , Genazzani AD , Luisi S , Luisi M , Petraglia F , Genazzani AR
Published: January 2005

OBJECTIVE: Neurosteroids have been suggested to be involved in the regulation of cognitive performances. A major neurosteroid gamma-aminobutyric acid (GABA) agonist is allopregnanolone: the main source of circulating allopregnanolone is the adrenal cortex. Studies indicated that a disturbance of the central regulation of the hypothalamic-pituitary-adrenocortical axis occurs in both senile (Alzheimer's disease: AD) and vascular dementia (VD). DESIGN: The aim of the present study was to evaluate the levels of circulating allopregnanolone, dehydroepiandrosterone (DHEA) and cortisol and their response to corticotropin-releasing factor (CRF) test in AD and VD. METHODS: Three groups of 12 subjects were included in the study: AD, VD and age-matched control subjects. CRF test was performed in all subjects and allopregnanolone, DHEA and cortisol levels were measured every 15min for 2h. RESULTS: Mean +/- s.e.m. allopregnanolone and DHEA basal levels were significantly lower in AD and VD than in controls, while cortisol levels were significantly higher than in controls (P<0.01). Allopregnanolone and DHEA levels increase in response to CRF test in all subjects but the area under curve (AUC) in patients was significantly lower than in controls (P<0.01). Cortisol secretion appeared to be very sensitive in response to CRF stimulation: in fact, cortisol response to CRF test in AD and VD subjects was higher (both as AUC and as % max increase) than in controls (P<0.01). CONCLUSIONS: The present study firstly showed that allopregnanolone levels are reduced both in AD and in VD and that dementia has a preserved stimulated response of allopregnanolone to CRF. Overall, however, the total response of allopregnanolone to CRF remains reduced in respect to controls. Further studies are necessary for a better understanding of the role of neurosteroids in the regulation of cognitive function.
Decreased ligand affinity rather than glucocorticoid receptor down-regulation in patients with endogenous Cushing's syndrome
Authors: Huizenga NA , De Herder WW , Koper JW , de Lange P , v Lely D AJ , Brinkmann AO , de Jong FH , Lamberts SW
Published: January 2005

OBJECTIVE: Glucocorticoids (GCs) serve a variety of important functions throughout the body. The synthesis and secretion of GCs are under the strict influence of the hypothalamo-pituitary-adrenal axis. The mechanisms of action of GCs are mediated by the intracellular glucocorticoid receptor (GR). Over the years, many studies have been performed concerning the regulation of GR expression by GC concentrations. METHODS: In the present study, we determined the characteristics of the GR in peripheral mononuclear blood leukocytes (PBML) from thirteen patients with endogenous Cushing's syndrome and fifteen control subjects, using a whole cell dexamethasone binding assay. Furthermore, cortisol concentrations were determined in order to investigate a possible relationship between serum cortisol levels and receptor characteristics. RESULTS: There were no differences in mean receptor number between patients and controls. On the other hand, a significantly lower ligand affinity was identified in cells from patients with Cushing's syndrome compared with controls. A complete normalisation of the ligand affinity was observed after treatment in the only patient tested in this respect, whereas the receptor number was not affected. In patients, there was a statistically significant negative correlation between cortisol concentrations and ligand affinity, which was not found in controls. CONCLUSION: Receptor down-regulation does not occur in PBML from patients with endogenous Cushing's syndrome. On the other hand, there seems to be a diminished ligand affinity which possibly reflects receptor modification in response to exposure to the continuously high cortisol levels in patients with Cushing's syndrome. This assumption is substantiated by the fact that in one patient a normalisation of the ligand affinity after complete remission of the disease was seen.
Unexplained habitual abortion is associated with a reduced endometrial release of soluble intercellular adhesion molecule-1 in the luteal phase of the cycle
Authors: Gaffuri B , Airoldi L , Di Blasio AM , Vigano P , Miragoli AM , Santorsola R , Vignali M
Published: January 2005

Although the mechanisms causing recurrent spontaneous abortion (RSA) remain frequently speculative, recent evidence indicates that a specific uterine immune-endocrine network plays a pivotal role in the continuation of pregnancy. We have recently demonstrated that an adhesion molecule of the immune system, named intercellular adhesion molecule (ICAM)-1, is markedly expressed at both protein and mRNA levels in endometrial stromal cells and is able to mediate their interaction with lymphoid cells. Moreover, we have shown that the soluble form of ICAM-1 (sICAM-1) can be released by the endometrium in a hormone-dependent manner. The present study was designed to determine whether surface and/or sICAM-1 expression by cultured endometrial stromal cells could be related to early pregnancy loss in patients with a history of unexplained RSA. Luteal-phase endometrial biopsies were obtained from eight patients who had experienced three or more consecutive unexplained RSAs in the first trimester and 12 control fertile women. Surface ICAM-1 was similarly expressed on luteal-phase endometrial cells obtained from women with and without a history of unexplained RSA. In contrast, the endometrial release of sICAM-1 was significantly lower in abortion-prone patients than in control women. sICAM-1 is a cytokine-inducible molecule able to interfere with several immunological responses and the reduced levels of the protein shed by the endometrium in patients who have suffered from unexplained RSAs may reflect the presence of an altered immunological environment during the early phases of pregnancy.
Thyrocyte release of asymmetric dimethylarginine does not account for human thyrocyte inhibition of endothelial cell cyclic GMP
Authors: Millatt LJ , Johnstone AP , Nussey SS , Whitley GS
Published: January 2005

BACKGROUND: The thyroid gland produces and responds to the signalling molecule nitric oxide (NO). The activity of NO synthase (NOS) may be regulated by endogenous NOS inhibitors such as asymmetric dimethylarginine (ADMA). OBJECTIVE: To investigate whether human thyrocytes are capable of regulating NOS activity via the production of ADMA. DESIGN: Human thyrocytes were incubated with human umbilical vein endothelial cells (HUVEC) in order to determine the effect on HUVEC NOS activity. HUVEC cGMP production over a 3-h period was measured as an indicator of NOS activity in the absence and presence of thyrocytes. To determine thyrocyte production of ADMA, samples of conditioned media were analysed by HPLC. RESULTS: The presence of primary human thyrocytes or immortalized human thyrocyte SGHTL-189 cells caused a significant inhibition of both basal (approximately 57% inhibition) and thrombin-stimulated (approximately 42% inhibition) HUVEC cGMP production. Both primary human thyrocytes and SGHTL-189 cells released ADMA (approximately 0. 28 microg per 10(6) thyrocytes over a 3-day period). However, excess L-arginine, the natural substrate for NOS, was unable to overcome thyrocyte inhibition of HUVEC cGMP production. CONCLUSION: These data indicate that human thyrocytes potently reduce endothelial cell cGMP concentrations, and that thyrocytes produce the endogenous NOS inhibitor, ADMA. However, the inhibition of endothelial cGMP is not mediated via thyrocyte production of a competitive NOS inhibitor.
Calcium stimulates parathyroid hormone-related protein production in Leydig tumor cells through a putative cation-sensing mechanism
Authors: Buchs N , Manen D , Bonjour JP , Rizzoli R
Published: January 2005

The production of parathyroid hormone-related protein (PTHrP) is regulated by a variety of hormones and growth factors. Previous research has shown that several PTHrP-producing cells are influenced by extracellular calcium (Ca(2+)(o)) concentration, with elevated levels increasing PTH-like activity released by cultured H500 rat Leydig tumor cells through a post-transcriptional mechanism. We have investigated the hypothesis that calcium stimulates PTHrP production in H500 cells by interacting with a cell membrane-associated cation-sensing receptor. Besides increased Ca(2+)(o) concentration, magnesium and the polycationic antibiotic neomycin also increased PTHrP production in a concentration-dependent manner. In the presence of the calcium ionophore, ionomycin, which markedly elevated cytosolic free calcium, the stimulation by Ca(2+)(o) of PTHrP could still be detected. These results indicate that increasing Ca(2+)(o) stimulates PTHrP production, possibly through a putative cell membrane-associated calcium-sensing mechanism. RT-PCR revealed the presence of a very small amount of calcium-sensing receptor coding mRNA.
O-glycosylation delays the clearance of human IGF-binding protein-6 from the circulation
Authors: Marinaro JA , Casley DJ , Bach LA
Published: January 2005

OBJECTIVE: The actions of insulin-like growth factors (IGF-I and IGF-II) are modulated by a family of six structurally related, high-affinity binding proteins (IGFBPs 1-6). IGFBP-6, an O-linked glycoprotein, preferentially binds IGF-II and inhibits its actions. The aim of this study was to investigate whether O-glycosylation modulates the pharmacokinetics of IGFBP-6. DESIGN AND METHODS: The pharmacokinetic profiles of (125)I-labelled glycosylated (g) and non-glycosylated (n-g) recombinant human IGFBP-6 were studied following intravenous bolus administration in anaesthetised rats. RESULTS: The redistribution half-life of gIGFBP-6 was 2.3-fold greater than that of n-gIGFBP-6 (14.4+/- 1.2 vs 6.3+/-1.5 min, P=0. 006). The elimination half-life of gIGFBP-6 was 21-fold greater than that of n-gIGFBP-6 (584.2+/-130.2 vs 28.0+/-4.2 min, P=0.019). The effect of O-glycosylation on IGFBP-6 pharmacokinetics was not due to inhibition of intravascular proteolysis. Radioactivity was found in stomach, kidneys, lung, spleen, heart and liver but not brain 4h after injection of g or n-gIGFBP-6. CONCLUSIONS: O-glycosylation delays the clearance of IGFBP-6 from the circulation and may therefore contribute to its role as a circulating inhibitor of IGF-II actions.
Atrial natriuretic peptide and aldosterone secretions, and atrial natriuretic peptide-binding sites in kidneys and adrenal glands of pregnant and fetal rats in late gestation in response to a high-salt diet
Authors: Deloof S , De Seze C , Montel V , Chatelain A
Published: January 2005

OBJECTIVE: This study aimed at determining, in the term pregnant rat, whether maternal and fetal plasma atrial natriuretic peptide (ANP) concentrations were modified in response to an oral sodium load, and to investigate whether any changes in plasma concentrations were able to modify the density and affinity of the different ANP-binding site subtypes in maternal and fetal kidneys and adrenal glands. METHODS: Pregnant rats kept in metabolic cages were divided into two groups. The normal sodium diet group had free access to rat chow and tap water whereas the high sodium diet group received 1% NaCl as drinking water for 10 consecutive days from day 11 to day 21 of gestation with free access to standard rat chow. Pregnant rats from both groups were killed by decapitation on day 21 of gestation. The plasma ANP and aldosterone concentrations were determined by RIA. The density and affinity of ANP receptors were determined in the maternal and fetal adrenal glands and kidneys. RESULTS: In the pregnant rats on the high-salt diet, the sodium and water intakes, as well as the urine volume and sodium excretion, were significantly higher than in the control group. After 10 days of high-salt intake, water and sodium retentions were not significantly different in the two groups, indicating that the pregnant rats were able to excrete excess salt. The high sodium intake did not change the body weight of the pregnant rats but did increase the body weight of the fetal rats. Maternal and fetal hematocrits remained unchanged in both groups, the high sodium intake did not modify plasma sodium concentration in the maternal rats but increased that of the fetuses, indicating an accumulation of sodium in the fetal rats. The dietary sodium intake did not change the plasma ANP concentrations but significantly decreased the plasma aldosterone concentrations in both the maternal and fetal rats. In response to the high-salt diet, the density and affinity of total ANP, ANPb and ANPc receptors were not altered in the maternal isolated renal glomeruli or the adrenal zona glomerulosa membranes or the fetal adrenal gland and kidney membrane preparations. CONCLUSION: These results suggest that ANP is not involved in the regulation of water and electrolyte balance in maternal and fetal rats during salt-loaded intake.
Three mRNA transcripts of the proopiomelanocortin gene in human placenta at term
Authors: Grigorakis SI , Anastasiou E , Dai K , Souvatzoglou A , Alevizaki M
Published: January 2005

The proopiomelanocortin (POMC) gene whose normal pituitary specific mRNA product is 1200 bases (b) is also expressed in placenta and its peptide derivatives such as ACTH and beta-endorphin may play an important role in the initiation of labor. So far, two mRNA transcripts, one small (800b) and one large (1380b) have been reported in placenta by Northern blot analysis, similar to other endocrine tissues and various extrapituitary tumors; however, it is questionable whether both of these transcripts are effectively translated to a functional protein. We examined by Northern blot analysis the size and the differential expression of placental POMC gene transcripts in pregnant women with different modes of delivery. Placental tissues were collected from two groups of pregnant women, six with vaginal delivery (VD) and five with cesarean section (CS). In both groups of placentae three POMC gene transcripts were detected of 800, 1200 and 1380 bases; the 1200b pituitary specific species often predominated and was always present. The 800b transcript was also always present, while the large transcript (1380b) was expressed in 3/6 VD and 2/5 CS placental tissues. No differences in the relative levels of any of these mRNA species showing effect of the mode of delivery were observed. We conclude that POMC gene transcription in placental tissue at term gives rise to three mRNA transcripts, thus resembling extrapituitary tumors. The reported changes in the levels of the derivative peptides according to the mode of delivery do not reflect changes in POMC mRNA levels and could be attributed to a post-translational effect.
Comparative analysis of follistatin-, activin beta A- and activin beta B-mRNA steady-state levels in diverse porcine tissues by multiplex S1 nuclease analysis
Authors: Schneider O , Nau R , Michel U
Published: January 2005

OBJECTIVE: The relation of activins (dimers of the beta-subunits of inhibin) and follistatin (FS) (their binding protein) affect the growth and differentiation of many cell types. Activin- and FS-mRNAs show a widespread co-expression throughout the organism, indicating an essential role for the FS/activin system in diverse physiological processes. The present study was performed to investigate FS-, activin betaA-, and activin beta B-mRNA expression in porcine tissues and to compare the relative mRNA tissue distribution by a newly developed multiplex S1 nuclease protection assay. METHODS: Twenty micrograms total RNA from different porcine tissues were subjected to multiplex S1 analysis. Specific mRNA expression was determined by measurements of optical densities on autoradiographs. RESULTS: Activin beta A-mRNA expression was abundant in the ovary, adrenal gland, fat, vein, artery and uterus, activin beta B-mRNA was highly expressed in the ovary, pituitary, uterus, placenta, aorta and cerebellum. FS-mRNA showed a widespread expression with high levels in ovary, uterus, cerebellum, placenta and fat. The comparison of relative activin beta A-, activin beta B- and FS-mRNA expression within a certain tissue showed a predominance of activin beta A-mRNA in the adrenal gland, fat, artery, spinal cord, cerebrum and colon and of activin beta B-m RNA in pituitary, testis and placenta, while FS-mRNA levels exceeded those of activin subunits in epididymis, liver, lymphoid tissue, muscle, intestine, cerebellum, ovary and uterus. CONCLUSIONS: The presented data provide an overview of FS-, activin beta A-, and activin beta B-mRNA steady state levels in porcine tissues.
Dynamics of bone turnover in children with GH deficiency treated with GH until final height
Authors: Baroncelli GI , Bertelloni S , Ceccarelli C , Cupelli D , Saggese G
Published: January 2005

OBJECTIVE: To examine the dynamics of bone turnover in children with growth hormone deficiency (GHD) during long-term treatment. DESIGN: We longitudinally measured growth velocity and serum concentrations of osteocalcin (OC), carboxyterminal propeptide of type I procollagen (PICP), and cross-linked carboxyterminal telopeptide of type I collagen (ICTP) in 24 patients with GHD during long-term GH treatment until final height (age: 7.7+/-0.7 and 16.9+/-0.5 years at baseline and at final height respectively). RESULTS: At baseline, OC, PICP, and ICTP levels were significantly (P<0.0001) reduced in comparison with prepubertal bone age-matched controls (10.2+/-2.3 microgram/l and 22.5+/-7.6 microgram/l; 187.8+/-26.2 microgram/l and 328. 4+/-74.3 microgram/l; 7.7+/-2.0 microgram/l and 14.2+/-1.3 microgram/l respectively). During the first year of treatment mean levels of the bone markers increased significantly (P<0.0001) with a peak at 12 months. After the first year of treatment, OC and PICP levels progressively declined, whereas ICTP levels remained stable until the final height; in any case, bone marker levels remained significantly higher (P<0.03-P<0.0001) than baseline. The change in bone marker levels at 6 and 12 months of treatment with respect to the baseline values was not related to growth rate during long-term treatment or final height. CONCLUSIONS: The results show that children with GHD have reduced bone turnover at baseline, and that long-term GH treatment is associated with a stimulation of bone turnover. OC, PICP, and ICTP do not predict growth rate during long-term treatment or final height in children with GHD.
Familial growth hormone deficiency with mutated GHRH receptor gene: clinical and hormonal findings in homozygous and heterozygous individuals from Itabaianinha
Authors: Hayashida CY , Gondo RG , Ferrari C , Toledo SP , Salvatori R , Levine MA , Ezabella MC , Abelin N , Gianella-Neto D , Wajchenberg BL
Published: January 2005

OBJECTIVE: To characterize clinically and hormonally the syndrome of autosomal recessive familial growth hormone deficiency (FGHD) recently identified in Itabaianinha, Sergipe, Brazil, caused by a novel mutation (mt) that inactivates the growth hormone-releasing hormone receptor (GHRH-R) gene. DESIGN: Clinical and hormonal evaluations were performed in 21 FGHD individuals (mt/mt group) aged 8 to 63 years, 13 heterozygotes for the GHRH-R mutation (wt/mt group) and 5 homozygotes for the wild type (wt) allele (wt/wt group), identified by genotyping of peripheral blood leukocyte DNA. METHODS: Clinical and hormonal characterization included physical examination and measurement of GH, IGF-I, IGF binding protein-3 (IGFBP-3), cortisol, prolactin, LH, FSH, and free thyroxine (FT4). RESULTS: Clinical features were consistent with isolated growth hormone deficiency. Height was significantly reduced in the mt/mt group compared with the wt/mt group (mean height standard deviation score (SDS) +/- s.d.: -7.35+/-1.37 vs -1.84+/-1.44 respectively, P<0. 0001), and the wt/wt group (-1.85 +/- 0.81, P=0.0007). The height of the 13 wt/mt subjects did not differ from the 5wt/wt individuals. Serum GH, IGF-I, IGF-I SDS, IGFBP-3 and IGFBP-3 SDS were all significantly lower in the mt/mt group than in the wt/mt and wt/wt groups. Two affected children treated with GH for 1 year showed a normal growth response. Serum IGF-I and IGF-I SDS were lower in wt/mt compared with wt/wt group, but did not reach statistical significance. IGF-I and IGF-I SDS correlated inversely with age in wt/mt group. CONCLUSIONS: FGHD due to an autosomal recessive GHRH-R gene mutation leads to marked dwarfism, phenotypically and hormonally indistinguishable from other forms of isolated GH deficiency. Heterozygotes for the GHRH-R mutation appear to have a partial defect in the GH/IGF axis, with no apparent height impairment.
Somatic trinucleotide change encompassing codons 882 and 883 of the RET proto-oncogene in a patient with sporadic medullary thyroid carcinoma
Authors: Bugalho MJ , Coelho I , Sobrinho LG
Published: January 2005

OBJECTIVE: Restriction analysis is a straightforward procedure for mutational analysis. It is commonly used for screening RET mutations. Incomplete digestion is a well-known cause of false results. Herein, we report another limitation of the method. DESIGN AND METHODS: Screening for somatic mutations in RET exons 16, 13 and 15 was performed in a patient with a sporadic medullary thyroid carcinoma. Genetic study was carried out by both restriction analysis and direct sequencing. RESULTS: A somatic trinucleotide change encompassing codons 882 and 883 of the RET proto-oncogene (GTA GCT to GTT TTT) was documented. Particular to this case is the silent mutation (GTA-->GTT) at codon 882. Independently, both the novel silent mutation and the missense mutation at codon 883 may disrupt the same AluI restriction site. Based on the restriction pattern we were able to say that both mutations occurred in the same allele. CONCLUSIONS: Restriction analysis is an easy approach for screening RET mutations; however, it is not enough to assign a final diagnosis.
Relationship between autoantibodies against glutamic acid decarboxylase, thyroglobulin/thyroid microsome and DNA topoisomerase II in the clinical manifestation of patients with type 1 diabetes mellitus in Taiwan
Authors: Shiau MY , Tsai ST , Hwang J , Wu CY , Chang YH
Published: January 2005

OBJECTIVE: In a preliminary cross-sectional study, we discovered that DNA topoisomerase II autoantibodies (anti-TopII) were detected in 49.2% of 195 Chinese type 1 diabetes mellitus (type 1 DM) patients with a mean age of 14.5 years and a mean duration of disease of 4.6 years. In order to demonstrate the relationship between anti-TopII and other immunological characteristics in Chinese type 1 DM patients, and to evaluate its putative prediction efficacy in Chinese patients, we simultaneously examined the frequency of anti-glutamic acid decarboxylase autoantibodies (anti-GAD), anti-TopII, antithyroglobulin/antimicrosomal autoantibodies (ATA/AMiA) and C-peptide concentrations in our patients in the present study. DESIGN AND METHODS: The frequency of anti-GAD and C-peptide levels, anti-TopII, and ATA/AMiA were examined in our patients by radioimmunoassay, enzyme-linked immunosorbant assay and hemagglutination respectively. Univariate comparisons were performed using Student's t-test for normal distributed data and Chi-square test for diclomatous data. Multivariate analysis was used for interpreting the independent risk factors which increased the incidence of anti-TopII. RESULTS AND CONCLUSIONS: The positivities for anti-GAD, anti-TopII, ATA/AMiA and C-peptide were 45.8%, 50.2%, 13.4% and 11.4% respectively. Anti-GAD and anti-TopII frequencies in our patients were similar when we stratified the patients by age, age at onset and duration. These observations imply that anti-GAD and anti-TopII remain persistent in Chinese patients with long-term type 1 DM duration. The most interesting finding is that anti-TopII frequency is more persistent than anti-GAD in our patients, especially when the diabetic duration is longer than 11 years. This indicates that anti-TopII, rather than anti-GAD, might act as a better indicator for monitoring the pathogenesis of Chinese type 1 DM patients especially in patients with a long-standing duration of disease. The late age of onset (>18 years) is a risk factor which increased the incidence of anti-TopII according to multivariate analysis. We further analyzed different manifestations between the youth- and adult-onset type 1 DM and found that adult-onset type 1 DM is characterized by better preservation of residual beta-cell function and higher frequencies of autoantibodies.
Prevalence of positive anti-neutrophil cytoplasmic antibody (ANCA) in patients receiving anti-thyroid medication
Authors: Gunton JE , Stiel J , Clifton-Bligh P , Wilmshurst E , McElduff A
Published: January 2005

OBJECTIVE: Vasculitis is a rare complication of anti-thyroid medications. There are 32 cases of anti-neutrophil cytoplasmic antibody (ANCA)-positive vasculitis in association with anti-thyroid medication reported in the English literature. The objectives of this study were to assess the frequency of positive ANCA in patients on long-term anti-thyroid medication, and to follow patients prospectively from commencement of medication to determine whether they became ANCA-positive after therapy. DESIGN: Prospectively collected cross-sectional study of two groups of patients: (i) who had received long-term (>18 months) anti-thyroid medication, and (ii) newly diagnosed thyrotoxicosis before commencement of anti-thyroid medication attending clinic between 28 April 1998 and 30 September 1998. Data were collected for age, sex, ethnicity, underlying thyroid disease, medication and duration, and symptomatology. RESULTS: Eight of 30 patients on long-term anti-thyroid medication (26.7%) were ANCA-positive. All ANCA-positive patients were female, seven were taking propylthiouracil (PTU) at the time of testing. ANCA-positive patients had taken PTU for a mean +/- s.d. of 7.9+/-10.2 years, compared with 0.8+/-2.2 years in ANCA-negative patients (Mann-Whitney, P<0.0001). The ten patients with newly diagnosed thyrotoxicosis were ANCA-negative before commencement of carbimazole. One (10%) became ANCA-positive within 8 months of therapy. CONCLUSIONS: In our population, ANCA-positivity in association with long-term anti-thyroid medication is common (26.7%). One patient who was ANCA-negative prior to anti-thyroid therapy has become ANCA-positive. ANCA should be tested in patients receiving long-term anti-thyroid medications, and in patients with adverse reactions. As PTU is more commonly associated with vasculitis and positive ANCA, carbimazole may be the preferred medication for long-term use. Patients with positive ANCA should be followed, and considered for definitive anti-thyroid therapy, to allow cessation of medication. ANCA-positivity may resolve after cessation of anti-thyroid medication.
Thyroid volumes in a national sample of iodine-sufficient swiss school children: comparison with the World Health Organization/International Council for the control of iodine deficiency disorders normative thyroid volume criteria
Authors: Hess SY , Zimmermann MB
Published: January 2005

OBJECTIVE: The determination of goiter prevalence in children by thyroid ultrasound is an important tool for assessing iodine deficiency disorders. The current World Health Organization/International Council for the Control of Iodine Deficiency Disorders (WHO/ICCIDD) normative values, based on thyroid volume in iodine-sufficient European children, have recently been questioned, as thyroid volumes in iodine-sufficient children from the USA and Malaysia are smaller than the WHO/ICCIDD reference data. Our objective was to describe ultrasonographic thyroid volumes in a representative national sample of iodine-sufficient Swiss school children, and to compare these with the current reference data for thyroid volume. DESIGN AND METHODS: A 3-stage, probability proportionate-to-size cluster sampling method was used to obtain a representative national sample of 600 Swiss children aged 6-12 years. The following data were collected: thyroid size by ultrasound, urinary iodine concentration, weight, height, sex and age. RESULTS: The median urinary iodine concentration (range) of the children was 115 microgram/l (5-413). Application of the WHO/ICCIDD thyroid volume references to the Swiss children resulted in a prevalence of 0%, using either age/sex-specific or body surface area (BSA)/sex-specific cut-off values. Upper limits of normal (97th percentile) of thyroid volume from Swiss children calculated using BSA, sex and age were similar to those reported in iodine-sufficient children in the USA, but were 20-56% lower than the corresponding WHO/ICCIDD references. CONCLUSIONS: Swiss children had smaller thyroids than the European children on which the WHO/ICCIDD references are based, perhaps due to a residual effect of a recent past history of iodine deficiency in many European regions. However, there were sharp differences between our data and a recent set of thyroid volume data in Swiss children produced by the operator and equipment that generated the WHO/ICCIDD reference data. This suggests that interobserver and/or interequipment variability may contribute to the current disagreement on normative values for thyroid size by ultrasound in iodine-sufficient children.
From guidelines to hospital practice: reducing inappropriate ordering of thyroid hormone and antibody tests
Authors: Toubert ME , Chevret S , Cassinat B , Schlageter MH , Beressi JP , Rain JD
Published: January 2005

OBJECTIVE: Because of major technical improvements and conscious care about cost effectiveness, limiting the inadequate use of thyroid biological tests appears to be a major issue. DESIGN: To (i) estimate the ordering prevalence of each thyroid test, (ii) assess the prevalence of relevant thyroid tests, and (iii) evaluate the impact of expressing justification for tests during a 2-month intervention period on these prevalences. METHODS: During a prospective 2-month survey (June-July 1997), all the request forms were divided into four groups of prescription: (1) investigation of thyroid function, (2) taking drugs affecting the thyroid, (3) monitoring of nodule and cancer, and (4) investigation of thyroid autoimmunity. Their appropriateness was thus determined according to consensus in our hospital and previously published recommendations. Results were compared with those of retrospective similar 2-month periods in 1996 and 1998. Combinations of thyroid function tests and thyroid antibodies were analyzed during the 1996, 1997 and 1998 periods. RESULTS: The overall estimated rate of appropriate ordering between 1996 and 1997 increased from 42.5% to 72.4% (P<10(-4)), with a significant improvement in each group of main diagnosis referral, except in group 3 where suitability was always over 85%. However, in group 4, appropriateness remained low (36%). Combinations of thyroid tests revealed an increase in single TSH order forms and single autoantibodies to thyroperoxidase (TPOAb) ones, while TSH+free thyroxine+free tri-iodothyronine and TPOAb+ autoantibodies to thyroglobulin ones decreased significantly. Interestingly, all these changes were maintained 1 year later (June-July 1998) even though physicians were not aware of this new study. CONCLUSIONS: Persistent change in medical practice was thus assessed.
The value of dehydroepiandrosterone sulfate measurement in the differentiation between benign and malignant adrenal masses
Authors: Terzolo M , Ali A , Osella G , Reimondo G , Pia A , Peretti P , Paccotti P , Angeli A
Published: January 2005

OBJECTIVE: Owing to their increasing rate of discovery as incidental findings, the characterization of adrenal masses is an important diagnostic problem which frequently challenges the clinician's skill. DESIGN: The results of dehydroepiandrosterone sulfate (DHEAS) measurement were evaluated in a consecutive series of 107 patients with an adrenal mass (39 men, 68 women aged 15-81 years, median 56 years). DHEAS levels observed in the patients were categorized as reduced, normal or elevated according to sex- and age-adjusted reference ranges obtained by measuring DHEAS in 214 healthy women and 142 healthy men aged 17-93 years. The working hypothesis was that a low DHEAS level is a marker of benignity. METHODS: In 84 patients, the adrenal mass was discovered serendipitously, while in the remainder the mass was clinically symptomatic. Patients with known extra-adrenal malignancies were excluded. The adrenal masses were categorized as benign or malignant by computerized tomography (CT) criteria. All patients with suspected malignant tumors or with overtly hypersecreting tumors underwent adrenalectomy. The patients with a presumptive benign tumor were followed-up for at least 12 months. RESULTS: In the overall series, the sensitivity and specificity of a low DHEAS level in the identification of a benign lesion were 41% and 100% respectively. Superimposable figures were obtained when considering only adrenal incidentalomas. DHEAS levels in adrenal cancers displayed some overlap with adrenal adenomas, but in only 2/11 adrenal cancers were DHEAS levels normal, while they were elevated in the remainder. CONCLUSIONS: The present data suggest that DHEAS measurement may help to differentiate benign from malignant adrenal masses as a complementary test of CT in a clinical research setting. The value of DHEAS measurement in general practice is limited because it may be difficult to differentiate between low and low-normal values, particularly in the elderly.
Use of a long-acting gonadotrophin-releasing hormone analogue in a postmenopausal woman with hyperandrogenism due to a hilus cell tumour
Authors: Picon MJ , Lara JI , Sarasa JL , Recasens JD , Clouet R , Gonzalo MA , Rovira A
Published: January 2005

OBJECTIVE: The aim of this study was to prove the utility of GnRH analogues for the suppression of androgen secretion in a postmenopausal woman with a suspected virilizing ovarian tumour. DESIGN AND METHODS: We present a case of a 72-year-old woman with virilization of recent onset. Hormonal studies revealed a fourfold increase in serum testosterone levels, normal dehydroepiandrosterone sulphate concentrations and high levels of serum 17-hydroxyprogesterone levels. Computed axial tomography scan of the ovaries was normal and the adrenal glands showed a discrete enlargement. The long-acting GnRH analogue, triptorelin, was injected initially (3.75mg i.m.) and serum hormone levels were measured weekly throughout one month. RESULTS: GnRH produced a decrease in serum testosterone levels to normal values, in parallel with the suppression of serum LH and FSH concentrations. The patient was treated for three months with triptorelin and she experienced an amelioration of the hyperandrogenic symptoms. In order to achieve a diagnosis, the patient was submitted to a laparotomy that revealed a small hilus cell tumour in the left ovary. CONCLUSION: GnRH analogues may offer a good therapeutic option in some states of gonadotrophin-dependent hyperandrogenism of ovarian origin.
The effect of human growth hormone on the carbohydrate units in arterial basement membrane-like material
Authors: Ledet T , Heickendorff L
Published: January 2005

OBJECTIVE: The present study focuses on the pathogenesis of the large vessel disease in diabetes. The arterial wall from diabetic individuals displays characteristic alterations of the extracellular matrix. Other observations show that the metabolism is changed with increased levels of growth hormone in diabetes. DESIGN: The effects of growth hormone on the carbohydrate composition in the basement membrane around the arterial smooth muscle cells were investigated. METHODS: Basement membrane material was obtained from cultures of smooth muscle cells by sonication and differential centrifugation after labeling with either [(3)H]glucose or [(3)H]glucosamine. The proportions of galactose, glucose, mannose, xylose, fucose and glucosamine were evaluated after addition of 45.45pmol/l human growth hormone. Also, the proportion of glycopeptides generated from the basement membrane was analyzed after fractionation on a combination of a Concanavalin A and a Pea Sepharose column. RESULTS: The proportion of galactose and glucose was changed, and the incorporation of [(3)H]glucosamine was reduced. The proportion of glycopeptides containing high mannose moities was increased as well as that of triantinary glycopeptides with internal fucose residues. CONCLUSION: The current in vitro data indicates that growth hormone may change the carbohydrate composition of the arterial basement membrane.
Effect of blockade of postsynaptic H1 or H2 receptors or activation of presynaptic H3 receptors on catecholamine-induced stimulation of ACTH and prolactin secretion
Authors: Willems E , Knigge U , Jorgensen H , Kjaer A , Warberg J
Published: January 2005

The effect of inhibition of the neuronal histaminergic system by blockade of postsynaptic H1 or H2 receptors or activation of presynaptic H3 autoreceptors on the ACTH and prolactin responses to the catecholamines epinephrine and norepinephrine was investigated in conscious male rats. Intracerebroventricular infusion of epinephrine and norepinephrine stimulated ACTH and prolactin secretion. Prior intracerebroventricular infusion of the H1 receptor antagonist, mepyramine, or the H2 receptor antagonist, cimetidine, had no effect on the ACTH response to epinephrine or norepinephrine, while these responses were inhibited by pretreatment with the H3 receptor agonist, imetit. The prolactin response to norepinephrine was significantly inhibited by pretreatment with mepyramine, cimetidine or imetit whereas the three histaminergic compounds had no effect on the prolactin response to epinephrine. The findings suggest that the histaminergic system exerts a mediating or permissive action on the norepinephrine-induced stimulation of prolactin secretion, whereas an intact histaminergic system may not be required for catecholamines to stimulate ACTH secretion. The inhibitory effect of imetit on catecholamine-induced release of ACTH may be due to an activation of H3 receptors located presynaptically on non-histaminergic neurons, e.g. aminergic neurons. The study further indicates an important role of histamine in the neuroendocrine regulation of prolactin secretion.
Expression of low and high density lipoprotein receptor genes in human adrenals
Authors: Liu J , Heikkila P , Meng QH , Kahri AI , Tikkanen MJ , Voutilainen R
Published: January 2005

Corticosteroids are synthesized from cholesterol which may arise from de novo synthesis or from the uptake of low or high density lipoproteins (LDL or HDL). In the present study, we compared the expression and regulation patterns of LDL receptor and CLA-1 (CD36 and LIMPII Analogous-1, an HDL receptor) genes in adult human adrenocortical tissues to shed more light on the relative contribution of LDL and HDL in human adrenal steroidogenesis. By screening 64 normal and pathological adrenal samples by Northern blotting, we found a positive correlation between LDL receptor and CLA-1 mRNA expression in the adrenal tissues (r=0.547; spearman rank correlation test P<0.01). Adrenal tissues adjacent to Cushing's adenomas contained consistently less LDL receptor and CLA-1 mRNA than normal adrenals (Mann-Whitney P<0.05). In primary cultures of normal adrenal cells, accumulation of both LDL receptor and CLA-1 mRNAs was upregulated by ACTH in a dose- and time-dependent manner, with an earlier induction of LDL receptor than CLA-1 mRNA expression. (Bu)(2)cAMP also increased the levels of these two mRNAs. Addition of LDL, but not HDL, into the culture medium increased cortisol production in untreated adrenocortical cells. Both LDL and HDL enhanced ACTH-induced cortisol production, with the effect of LDL much stronger than that of HDL. Our data show that LDL receptor and CLA-1's expression is ACTH-dependent and occurs in parallel in human adrenal tissues. LDL rather than HDL may be used as the preferential source of cholesterol for steroidogenesis in human adult adrenocortical cells.
Immunoreactive adrenomedullin (AM) concentration in maternal plasma during human pregnancy and AM expression in placenta
Authors: Kobayashi K , Kubota T , Aso T , Hirata Y , Imai T , Marumo F
Published: January 2005

Adrenomedullin (AM) is a novel vasorelaxant peptide, isolated from human pheochromocytoma. Although AM may be involved in the regulation of the cardiovascular system, a number of other mechanisms are also involved. The present study was undertaken to confirm the presence of AM in human maternal circulation and in placental function during pregnancy. Immunoreactive (ir) AM concentrations in maternal plasma were 3.4+/-0.7fmol/ml (mean+/-s.e. m.) in the first trimester, 3.3+/-1.1fmol/ml in the second trimester, 7.3+/-2.8fmol/ml in the third trimester, 4.1+/-1.9fmol/ml in early puerperium and 3.0+/-0.4fmol/ml in non-pregnant periods; the concentration in the third trimester was significantly greater than those in other periods. Plasma concentrations of estradiol (E(2)), progesterone, human placental lactogen (hPL) and human chorionic gonadotropin (hCG) were also measured, using RIA kits. Significant correlations have been demonstrated between the concentrations of irAM and those of E(2), progesterone and hPL. We therefore examined the expression of AM within the placental tissues using immunohistochemistry and northern blot analysis in order to demonstrate a correlation between the presence of AM in the placenta and maternal plasma. Using immunohistochemistry, we detected AM in the amnion at term and the expression of AM mRNA in human placental tissues using cloned human (h) AM complementary DNA as a probe. This study demonstrates the immunoreactivity of human hAM in maternal plasma during pregnancy, and suggests that hAM in maternal plasma is generated partly from placental tissue.
Multiple endocrine neoplasia type 1 gene expression is normal in sporadic adrenocortical tumors
Authors: Zwermann O , Beuschlein F , Mora P , Weber G , Allolio B , Reincke M
Published: January 2005

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder with neoplasia of the anterior pituitary, the parathyroid, the endocrine pancreas and other endocrine tissues including the adrenal cortex. The tumor-suppressor gene causing this disease was identified at the gene locus 11q13. We recently reported that adrenocortical carcinomas frequently show loss of heterozygosity (LOH) of 11q13, but do not contain point mutations within the MEN1-coding region. To investigate whether reduced gene expression (for example by mutations within the MEN1 promoter) may contribute to the tumorigenesis of sporadic adrenocortical tumors, 24 adrenocortical specimen were studied by Northern blot analysis. This series included six adrenocortical carcinomas, four cortisol-producing adenomas, six aldosterone-producing adenomas, three endocrine-inactive adenomas and six normal adrenal glands. The presence of LOH of 11q13 was investigated using five polymorphic microsatellite markers (D11S956, PYGM, D11S4939, D11S4946 and D11S987) close to the MEN1 gene. Poly-A mRNA was hybridized with a PCR-generated cDNA probe of the MEN1 gene, a cDNA of the former MEN1 candidate gene phospholipase (PLC) beta3 and a mouse beta-actin cDNA for normalization. LOH of 11q13 was detected in five out of six carcinomas and two inactive adenomas, but in none of the hormone-producing adenomas. Compared with normal adrenals (100+/-6. 5%, mean+/-s.e.m.) MEN1 mRNA in adrenocortical tumors was expressed in similar amounts (carcinomas 109+/-11%, cortisol-producing adenomas 131+/-10%, aldosterone-producing adenomas 113+/-13%, endocrine-inactive adenomas 111+/-2%) with the exception of one adrenocortical carcinoma with low MEN1 mRNA expression (66%). PLCbeta3 mRNA expression showed a variable pattern without reaching significant differences between the groups. We conclude that since mRNA levels were unaltered in the majority of tumors, mutations of the MEN1 gene causing altered gene transcription is unlikely to be a major pathogenic factor of sporadic adrenocortical tumors.
Novel insights into the neuroendocrinology of critical illness
Authors: Van den Berghe G
Published: January 2005

An unexplained hallmark of prolonged critical illness is the fact that food does not prevent or reverse protein wasting, while fat is paradoxically accrued. This 'wasting syndrome' often persists after the underlying disease has been resolved and thus perpetuates intensive care dependency. Although the crucial role of an intact hypothalamus-pituitary axis for homeostasis during stress is well recognized, the differences between the neuroendocrine changes observed in acute and prolonged critical illness were only recently described. Novel insights in this area are reviewed here. The initial endocrine stress response consists primarily of a peripheral inactivation of anabolic pathways while pituitary activity is essentially amplified or maintained. These responses presumably provide the metabolic substrates and host defense required for survival and to delay anabolism, and thus should be considered as adaptive and beneficial. Persistence of this acute stress response throughout the course of critical illness was hitherto assumed. This assumption has now been invalidated, since a uniformly reduced pulsatile secretion of ACTH, TSH, LH, prolactin (PRL) and GH has been observed in protracted critical illness, causing diminished stimulation of several target organs. Impaired pulsatile secretion of anterior pituitary hormones in the chronic phase of critical illness seems to have a hypothalamic rather than a pituitary origin, as administration of relevant releasing factors evoked immediate and pronounced pituitary hormone release. A reduced availability of TRH, one of the endogenous ligands of the GH-releasing peptide (GHRP) receptor (such as the recently discovered ghrelin) and, in very long-stay critically ill men, also of GHRH, appear to be involved. This hypothesis was further explored by investigating the effects of continuous i.v. infusion of GHRH, GHRP, TRH and their combinations for several days. Pulsatile secretion of GH, TSH and PRL was re-amplified by relevant combinations of releasing factors which also substantially increased circulating levels of IGF-I, GH-dependent binding proteins, thyroxine and tri-iodothyronine (T3) while avoiding a rise in reverse T3. Active feedback-inhibition loops prevented overstimulation of target organs and metabolic improvement was noted with the combined infusion of GHRP and TRH. Whether this novel endocrine strategy will also enhance clinical recovery from critical illness remains to be explored.