bluuebunny/crossref_metadata_2025 huggingface dataset:
CYP21 analysis and phenotype/genotype relationship in the screened population of the Italian Emilia–Romagna region
Authors: Balsamo  , Cacciari Emanuele , Baldazzi Lilia , Tartaglia Lucia , Cassio Alessandra , Mantovani Vilma , Piazzi Sandro , Cicognani Alessandro , Pirazzoli Piero , Mainetti Benedetta , Zappulla Franco
Published: March 2003

OBJECTIVES

We have genotyped the patients with congenital adrenal hyperplasia due to 21‐hydroxylase deficiency identified from March 1980 to December 1997 through a combined program of neonatal screening and case survey in the Emilia–Romagna Region (Italy). We have also analysed retrospectively the possible advantages of genotypical neonatal classification.

DESIGN

A ‘phase A’ of screening and clinical monitoring (March 1980–September 1983 and March 1991–December 1997) and a ‘phase B’ of clinical monitoring only (October 1983–February 1991) were taken into account.

PATIENTS

A total of 61 patients (20 salt wasting, nine simple virilizing and 32 nonclassical forms) were genotyped, HLA typed and hormonally tested to understand better the genotype/phenotype relationship and the epidemiology and geographical distribution of associated mutations. The fully genotyped patients were classified into four mutation groups according to the degree of enzymatic activity (‘null’ and ‘A’ to ‘C’).

RESULT

The most frequent genotype alterations were deletion (24.1% classical, 3.3% nonclassical forms), large gene conversion (9.2% classical, 1.7% nonclassical forms), In2 splice (27.7% classical, 15.0% nonclassical forms), I172N (5.5% classical, 10.0% nonclassical forms), V281L (3.7% classical, 43.3% nonclassical forms), P453S (5.0% nonclassical forms). A significant difference (χ2 = 5.101; P < 0.025) in the distribution of classical genotypes was found in Romagna (south‐east; incidence 1 : 7437 newborns) compared to Emilia (north‐west; incidence 1 : 25 090 newborns). Two putative new mutations were found in our population. Little discrepancy was found between genotype and phenotype.

CONCLUSIONS

The high frequency of genotypes ‘null’ or ‘A’ in the ‘phase A’vs. ‘phase B’ of our study confirms the usefulness of neonatal screening in preventing the death of male patients with salt wasting forms. The substantial similarity in the mutational spectrum of classical forms found in our study, based on the detection of all the classical patients of a specific area, leads us to believe that the distribution of mutations is due to the inherent characteristics of the gene locus, and that regional effects play a minor role. Prompt neonatal genotyping can be of valuable diagnostic assistance in neonatal screening for the confirmation of the diagnosis in newborns with moderately elevated 17 hydroxyprogesterone levels.
Thyroid function in wholly breast‐feeding infants whose mothers take high doses of propylthiouracil
Authors: Momotani Naoko , Yamashita Ryoko , Makino Fuminori , Noh Jaeduk Yoshimura , Ishikawa Naofumi , Ito Koichi , Ito Kunihiko
Published: March 2003

BACKGROUND

Propylthiouracil (PTU) might theoretically be preferred over methimazole (MMI) during breast‐feeding because of its lower milk/serum concentration ratio (0.1 vs. 1.0). The problem is that Graves' disease often relapses during the postpartum period, and high doses of PTU are sometimes needed to control maternal hyperthyroidism) during breast‐feeding. However, there are virtually no data on the effects of maternal PTU on thyroid status of infants whose mothers take more than 300 mg PTU daily and who are wholly breast‐feeding.

OBJECTIVES

To investigate whether mothers can breast‐feed without adverse effects on infants' thyroid status while taking 300 mg or more daily of PTU .

SUBJECTS AND DESIGN

Eleven infants who were wholly breast‐fed while their mothers took PTU 300–750 mg daily for Graves' hyperthyroidism were included in this study. In one of the 11 infants, the mother also took iodine 6 mg daily for a limited period. Thyroid status in these infants was evaluated.

MEASUREMENTS

Free T4 (FT4), thyrotrophin (TSH), and TSH binding inhibiting antibody (TBIAb) concentrations were examined at least once in the age range 6 days to 9 months. Maternal blood was also examined for FT4 and TBIAb on the same day, or within a week, of the infants' blood tests. FT4, TSH and TBIAb concentrations at birth were examined, using cord blood, in cases where antithyroid drugs had been continued through delivery.

RESULTS

Three of the 11 infants had TSH concentrations higher than the normal range for adults. In one of the three infants, the TSH concentration, which was determined 19 weeks after birth, was just above the normal range. In the remaining two infants whose mothers had taken PTU through delivery, TSH concentrations, determined within 7 days after birth, were distinctly high, but they became normal while maternal PTU doses were the same as or higher than those at the initial examination. Maternal PTU doses or FT4 concentrations were not significantly correlated with infants' TSH concentrations.

CONCLUSION

Mothers can breast‐feed while taking propylthiouracil at doses as high as 750 mg daily without adverse effects on thyroid status in their infants.
Characterization of a novel DNA polymorphism in the human CYP21 gene and application for DNA diagnosis of congenital adrenal hyperplasia
Authors: Lee Yong‐Ho , Park Eun‐Sook , Kang Shin‐Hye , Kim Hogeun , Lee Jin‐Yong , Lee Jin‐Sung
Published: March 2003

OBJECTIVES

Congenital adrenal hyperplasia (CAH) is a common endocrine disorder and CYP21 (21‐OH, EC 1.14.99.10) deficiency is the most common cause of the disease. The presence of a pseudogene and a wide range of mutation types often makes DNA diagnosis difficult. Analysis of mutant alleles from patients with CAH identified a new DNA polymorphism in exon 10. To test the usefulness of this polymorphism, linkage analysis was performed using three RFLP's at both end of the CYP21 gene in patients and controls.

DESIGN AND PATIENTS

Genomic DNA was extracted from 21 unrelated patients and 39 unaffected individuals. Haplotyping analysis was performed for three RFLPs, MspI and Fnu4HI in intron 2 and a new SmaI RFLP in exon 10. All three polymorphic sites were characterized by DNA sequencing and usefulness of these RFLPs for DNA diagnosis was tested in patients' families.

MEASUREMENT

CAH patients were diagnosed by clinical symptoms and biochemical tests. Allele frequencies and heterozygosities were studied for three RFLP's in patients and controls using polymerase chain reaction (PCR).

RESULTS

A new SmaI RFLP showed a sequence difference as G or A at the nucleotide position 2694 in exon 10. Sequences at the MspI and Fnu4HI polymorphic sites were T or C at the nucleotide position 395 and 453, respectively. All of these RFLPs showed biallelic DNA polymorphisms and codominant segregation in family analysis. Heterozygosities were 0.31 for MspI, 0.48 for Fnu4HI and 0.44 for SmaI in normal individuals. There was no linkage disequilibrium for three RFLPs between patients and controls.

CONCLUSIONS

The SmaI RFLP can be useful for linkage analysis and DNA diagnosis in conjunction with RFLPs in intron 2 in CAH families because the polymorphic site is within the active gene at the 3′ end. DNA sequencing results revealed that these RFLPs were created by gene conversions as with other mutations in the CYP21 gene.
Parathyroid hormone‐related protein in the aetiology of fibrous dysplasia of bone in the McCune Albright syndrome
Authors: Fraser William D. , Walsh Cathy A. , Birch Mark A. , Durham Brian , Dillon Jane P. , McCreavy David , Gallagher James A.
Published: March 2003

OBJECTIVE

Fibrous dysplasia, observed in bone lesions in the McCune Albright syndrome (MAS), is thought to result from abnormalities in cells of the osteogenic lineage associated with over‐activation of the cAMP signalling pathway in affected cells. The aim of this study was to investigate the role of parathyroid hormone‐related protein (PTHrP) in the aetiology of MAS, and to determine a possible therapeutic role for 1,25‐dihydroxy vitamin D3 (1,25(OH)2D3).

DESIGN

The effects of 1,25(OH)2D3 on PTHrP production and mRNA expression were determined in vitro. 1,25(OH)2D3 therapy was administered to three patients with MAS.

PATIENTS

Clinical data from four MAS patients (MAS1, 2, 3 and 4), and in vitro studies using bone from three MAS patients (MAS1, 2, and 3), are presented.

MEASUREMENTS

Immunoradiometric assay and low‐cycle number reverse transcriptase‐linked PCR were used to determine PTHrP production and mRNA expression in vitro. Standard clinical biochemistry was recorded pre and post commencement of 1,25(OH)2D3 treatment.

RESULTS

We report the elevated secretion of PTHrP, and a concomitant rise in PTHrP mRNA expression, in cultured osteoblasts from three MAS patients. Treatment with 1,25(OH)2D3 produced a dose‐dependent decrease in PTHrP protein secretion and mRNA expression. Marked improvement in bone biochemistry in MAS1, 2 and 3 post treatment with 1,25(OH)2 D3 is documented.

CONCLUSION

This study provides the first evidence suggesting that PTHrP may contribute to the aetiology of fibrous dysplasia in MAS. In addition, the therapeutic administration of 1,25(OH)2D3 may provide clinicians with an important new regime for symptomatic relief of bone pain and fracture in some patients with MAS.
Adrenal hyperandrogenism in adolescent girls with a history of low birthweight and precocious pubarche
Authors: Ibáñez Lourdes , Potau Neus , Marcos Maria Victoria , De Zegher Francis
Published: March 2003

OBJECTIVE

Girls with precocious pubarche (PP) are at increased risk for ovarian dysfunction, hyperinsulinism and dyslipidaemia in adolescence, in particular when PP is preceded by reduced fetal growth. However, it is not known whether PP girls still have adrenal hyperandrogenism after puberty and if so, which fraction of PP girls develops so‐called functional adrenal hyperandrogenism (FAH), an entity characterized by ACTH‐dependent 17‐ketosteroid excess.

PATIENTS AND DESIGN

Data were longitudinally collected from 47 girls with PP: at birth (weight for gestational age), at diagnosis of PP (age 6.7 ± 1.1 years) and in adolescence (age 15.0 ± 1.9 years).

MEASUREMENTS

Serum dehydroepiandrosterone sulphate (DHEAS) and androstenedione were measured at PP diagnosis, as well as the 17‐hydroxyprogesterone (17‐OHP) response to ACTH; postpubertal evaluation included assessment of adrenal and ovarian function, and of insulin responses to a glucose load. PP girls were considered to have FAH in adolescence if both DHEA and androstenedione responses to ACTH were excessive (> 1500 ng/dl and > 350 ng/dl, respectively).

RESULTS

At diagnosis of PP, girls had high DHEAS and androstenedione levels, as well as high 17‐OHP responses to ACTH. In adolescence, PP girls had a normal BMI, presented with mild hirsutism and had high baseline and post‐ACTH concentrations of most adrenal androgens, low SHBG levels and tended to have hyperinsulinemia and to present biological signs of ovarian hyperandrogenism. More than a third of the PP cohort developed FAH in adolescence. Neither baseline DHEAS, androstenedione, nor post‐ACTH 17‐OHP values at diagnosis of PP predicted the development of FAH in adolescence. In PP girls, only a low weight at birth was found to be significantly associated with subsequent FAH.

CONCLUSIONS

These longitudinal findings in girls with PP point to the possibility of an endocrine sequence of prenatal onset: low weight at birth, PP in childhood and adrenal hyperandrogenism in adolescence. The pathophysiological mechanisms underpinning this newly recognized sequence remain to be identified.
The effect of distinct activating mutations of the luteinizing hormone receptor gene on the pituitary–gonadal axis in both sexes
Authors: Latronico Ana Claudia , Lins Teresa Selma S. , Brito Vinicius Nahime , Arnhold Ivo Jorge P. , Mendonca Berenice B.
Published: March 2003

OBJECTIVE

Familial or sporadic male‐limited precocious puberty is a distinct and unusual gonadotrophin‐independent form of sexual precocity caused by constitutively activating mutations of the luteinizing hormone receptor (LHR). In the present study, we evaluated the effect of known activating mutations at different sites of the LHR gene on the pituitary–gonadal axis in both sexes.

PATIENTS

Four unrelated Brazilian boys (I‐IV) with gonadotrophin‐independent precocious puberty and two asymptomatic females (V‐VI), a sister and mother of two of the affected boys, were studied. Patients I, II and V carried the Ala568Val mutation located at the third intracellular loop of the LHR. Patient III carried the Leu457Arg mutation at the third transmembrane helix, and patients IV and VI carried the Thr577Ile mutation at the sixth transmembrane helix of the LHR.

MEASUREMENTS

Serum levels of LH, FSH, testosterone, and oestradiol under basal and GnRH‐stimulated conditions were determined in all patients. Testosterone levels were also measured after a hCG stimulation test in patient III.

RESULTS

Basal LH and FSH levels were prepubertal in all boys studied. The GnRH‐stimulated serum LH and FSH levels were prepubertal in three boys (I, II and IV), whereas patient III showed totally suppressed LH and FSH levels at ages 2 and 7 years (bone ages 6 and 14 years, respectively). Serum testosterone levels ranged from 3.8 to 69.5 nmol/l in the four boys. Patient III had the highest testosterone levels that did not respond to hCG stimulation. The 4 year‐old girl (patient V) was phenotypically normal and the acute response to GnRH was indicative of prepubertal status. Patient VI had normal menstrual cycles and fertility.

CONCLUSIONS

These findings indicate variable effects of LHR activating mutations on the pituitary–gonadal axis in boys that can result in lack of normal LH and FSH release. In contrast, prepubertal and adult females were asymptomatic and had normal basal and GnRH‐stimulated LH and FSH levels.
Construction and field validation of a self‐administered screener for testosterone deficiency (hypogonadism) in ageing men
Authors: Smith Kevin W. , Feldman Henry A. , McKinlay John B.
Published: March 2003

To design a self‐administered screening questionnaire to inform men about their risk for testosterone deficiency.

The screener was developed in two phases. First was a construction phase in which relevant risk factors and a scoring algorithm were defined from multiple logistic regression analyses of survey data. In the second phase, the screener's accuracy (based on sensitivity, specificity, and Receiver Operating Characteristic (ROC) curves) was tested using patients from a primary care clinic. All subjects provided blood samples for endocrine testing.

Survey data from 1660 men aged 40–79 years participating in the Massachusetts Male Ageing Study (MMAS) were analysed in the first phase. The clinic sample consisted of 304 men aged 40–79 years presenting at a large Massachusetts primary health care clinic for routine check‐ups or minor medical problems.

The primary outcome was testosterone deficiency, defined as serum total testosterone below 12·1 nmol/l. Self‐reported variables considered as potential risk factors included age, obesity, chronic diseases, health behaviour, the Jackson dominance scale, and symptoms of stress.

The prevalence of testosterone deficiency was 20·4% in the MMAS and 42·1% in the clinic sample. An eight‐item screener was developed based on age, body mass index, diabetes, asthma, headaches, sleep patterns, dominance preferences, and smoking status. The screener performed significantly better than chance in identifying men with low testosterone levels; the area under the ROC curve was 0·66 in the MMAS sample and 0·67 in the clinic sample.

The self‐scored screener developed in this study reliably detects men at risk of hypogonadism. The screener encourages at risk men to seek professional evaluation of their testosterone levels.
Toxic multinodular goitre in a patient with generalized resistance to thyroid hormone who harbours the R429Q mutation in the thyroid hormone receptor β gene
Authors: Taniyama Matsuo , Ishikawa Naofumi , Momotani Naoko , Ito Koichi , Ban Yoshio
Published: March 2003

The association of resistance to thyroid hormone (RTH) due to a receptor defect with toxic multinodular goitre or with carcinoma of the thyroid has not been previously reported. Previous histopathological studies of the thyroid gland in patients with RTH have revealed changes similar to multinodular goitre, probably due to continuous stimulation by TSH. We report here a case of generalized resistance to thyroid hormone associated with a multinodular goitre, which became toxic. The patient was a 46‐year‐old Japanese woman who noticed a goitre although she had no symptoms of thyrotoxicosis. Initial examination revealed elevated serum thyroid hormone levels and a normal TSH level. Ultrasonography disclosed a multinodular goitre with cystic lesions. Three years later, the patient complained that the goitre had become larger and that she had developed symptoms of thyrotoxicosis such as palpitation and hyperhydrosis. Progressive hyperthyroxinaemia with relatively suppressed TSH, increased radioiodine uptake and negative anti‐TSH receptor antibodies led to the diagnosis of toxic multinodular goitre. Subtotal thyroidectomy was performed, and pathological examination revealed a micropapillary carcinoma within the multinodular goitre. Occurrence of thyroid carcinoma should be considered in RTH because its incidence is high in multinodular goitre. Molecular examination revealed the R429Q mutation in the thyroid hormone receptor β gene, which is one of the mutations usually manifesting as the pituitary resistance phenotype. That thyrotoxic manifestations appeared only during toxic stage of multinodular goitre in this case suggests that the phenotype of this type of mutation can be dependent on the amount of thyroid hormone.
Oncogenic osteomalacia associated with mesenchymal tumour detected by indium‐111 octreotide scintigraphy
Authors: Rhee Yumie , Lee Jong Doo , Shin Kyoo Ho , Lee Hyun Chul , Huh Kap Bum , Lim Sung‐Kil
Published: March 2003

In a 40‐year‐old man who had suffered from vague and generalized bone pains for 7 years due to oncogenic osteomalacia, the causative tumour was finally detected by Indium‐111 octreotide scintigraphy. Some characteristics of the tumour associated with oncogenic osteomalacia, such as its size, growth rate, location and origin, often make the diagnosis difficult. However, the recent discovery of somatostatin receptors in mesenchymal tumours, which are the most common cause of oncogenic osteomalacia, has raised the possibility of early detection of this devastating disorder. Here, we report that radiolabelled octreotide scintigraphy has a potential role as a diagnostic tool in oncogenic osteomalacia. However, the exact role of somatostatin receptors in tumours associated with oncogenic osteomalacia still remains elusive.
Loss of gender difference in serum leptin levels and its slow recovery after successful surgery for Leydig cell tumours in two virilized females
Authors: Pekic S. , Vujovic S. , Spremovic‐Radjenovic S. , Petakov M. , Djurovic M. , Damjanovic S. , Micic D. , Dieguez C. , Casanueva F. F. , Popovic V.
Published: March 2003

One of the factors that predicts serum leptin levels is gender. It has been shown that sex steroid hormones, in particular testosterone, play an important role in the regulation of serum leptin levels. We had the opportunity to examine the effects of acute and chronic changes in serum testosterone levels on serum leptin concentrations in two virilized females harbouring testosterone‐secreting ovarian tumours, before and after curative surgery. Chronically elevated basal testosterone levels (46 nmol/l) were associated with suppressed serum leptin levels (1·46 µg/l and 2·56 µg/l) vs. 12 age‐ and BMI‐matched healthy subjects 9·89 ± 0·64 µg/l. Leptin levels were determined from pooled serum samples assayed by commercial radioimmunoassay. High testosterone levels abolished the well known sexual dimorphism of serum leptin levels. Two weeks after curative resection of these tumours serum leptin levels were unaltered and started to increase progressively after one month. One patient received parenteral conjugated oestrogens while the other resumed spontaneous menstrual cycles. Three months after curative surgery obvious changes in body composition were registered (DEXA). Six months later further rise in serum leptin concentrations occurred without further changes in body composition. In conclusion, leptin levels did not change in spite of rapid changes in the steroid milieu, but in the long term increase in body fat stores, new steroid milieu and maybe other factors are important determining factors of serum leptin levels.
Carbohydrate metabolism during long‐term growth hormone treatment in children with short stature born small for gestational age
Authors: Sas Theo , Mulder Paul , Aanstoot Henk Jan , Houdijk Mieke , Jansen Maarten , Reeser Maarten , Hokken‐Koelega Anita
Published: March 2003

OBJECTIVE

To assess possible side‐effects of long‐term continuous growth hormone (GH) treatment on carbohydrate (CH) metabolism in children with short stature born small for gestational age.

DESIGN

In a prospective, randomised double‐blind, dose–response multicentre trial, the effect of GH treatment on CH metabolism was evaluated, comparing two GH dosages [3 vs. 6 IU/(m2 body surface·day)].

PATIENTS

Seventy‐eight children with short stature (height SD‐score < − 1·88) born small for gestational age (birth length SD‐score < − 1·88) being all prepubertal with a mean (SD) chronological age of 7·3 (2·2) years before start of treatment.

MEASUREMENTS

Glucose and insulin concentrations during oral glucose tolerance tests (OGTTs) and glycosylated haemoglobin (HbA1c) were measured before and during 6 years of GH treatment.

RESULTS

Before treatment, the glucose response to oral glucose after 120 min was in six of the 78 children (8%) above 7·8 mmol/l but below 11·1 mmol/l, indicating impaired glucose tolerance (IGT), whereas after 6 years of GH treatment, IGT was found in 4% of the children. None of the children developed diabetes mellitus. Mean fasting glucose levels had increased significantly by 0·5 mmol/l after 1 year of GH treatment, without a further increase thereafter. The 2‐h area under the curve adjusted for fasting levels (AUCab) for glucose and the HbA1c levels were lower after 6 years of GH treatment compared to baseline. During GH treatment, all HbA1c levels were in the normal range. In contrast to the effects on glucose levels, GH treatment induced considerably higher fasting insulin levels and glucose‐stimulated insulin levels. The increase in AUCab for insulin occurred particularly during the first year of treatment, whereas the fasting insulin levels showed a further increase from one to six years. As a result, the 30‐ and 120‐min ratios of insulin to glucose were higher during GH treatment compared to the start of treatment. The children who remained prepubertal during the entire study period showed similar patterns in glucose and insulin levels compared to the children who entered puberty. None of the observed changes were different between the GH dosage groups.

CONCLUSIONS

Continuous GH treatment during 6 years in children with short stature born small for gestational age has no adverse effects on glucose levels, even with dosages up to 6 IU/(m2 d). However, as has been reported in other patient groups, GH treatment induces higher fasting insulin levels and glucose‐stimulated insulin levels, indicating relative insulin resistance. Since the consequences of long‐term hyperinsulinism during childhood are unknown, careful follow‐up of these GH‐treated children born small for gestational age is required.
Growth hormone (GH) secretion in children with Noonan syndrome: frequently abnormal without consequences for growth or response to GH treatment
Authors: Noordam C. , Van Der Burgt I. , Sweep C. G. J. , Delemarre‐van de Waal H. A. , Sengers R. C. A. , Otten B. J.
Published: March 2003

The role of GH insufficiency in the pathogenesis of short stature in Noonan syndrome is unclear.

Cross‐sectional study.

Seventeen patients with Noonan syn‐drome (13 boys, 4 girls; aged 4·8–13·3 (mean 9·2) years) and short stature before start of GH treatment.

Spontaneous 12‐h overnight GH secretion by continuous sampling analysed using Pulsar, plasma IGF‐I and IGFBP‐3 levels, and 24‐h urinary GH excretion were measured at start of GH treatment. A glucagon stimulation test was performed. Height and height velocity were monitored before and after 1 year of GH treatment. IGF‐I and IGFBP‐3 were remeasured after 1 year of GH treatment.

Nine of the 17 children had a mean overnight GH concentration below the lower limit of the normal range. In six of the 17 patients, overnight GH profiles showed high trough GH concentrations. Glucagon stimulation tests were normal in 16 of the 17 patients. Mean IGF‐I level was below normal (−0·4 SD). None of the parameters regarding GH secretion obtained from the overnight profile or provocative test was related to height or height velocity, nor to first year response to GH treatment. IGF‐I and IGFBP‐3 did not correlate with any of the GH secretion data. IGF‐I and IGFBP‐3 were related to height and height velocity at the start of GH treatment (r = 0·53 (P < 0·01) and r = 0·61 (P < 0·03) respectively). Rises in IGF‐I and IGFBP‐3 under GH treatment were related to the increment in height velocity (r = 0·70 (P < 0·01) and r = 0·71 (P < 0·02) respectively).

Abnormalities in GH secretion are frequent in patients with Noonan syndrome and short stature. These abnormalities were not related to auxology at start of or response to GH treatment. Clinically GH insufficiency is not important in Noonan syndrome and monitoring spontaneous GH secretion is not necessary before the start of GH treatment.
Influence of melatonin administration on glucose tolerance and insulin sensitivity of postmenopausal women
Authors: Cagnacci Angelo , Arangino Serenella , Renzi Antonietta , Paoletti Anna Maria , Melis Gian Benedetto , Cagnacci Paolo , Volpe Annibale
Published: March 2003

The effect of melatonin on human carbohydrate metabolism is not yet clear. We investigated whether melatonin influences glucose tolerance and insulin sensitivity in aged women.

Twenty‐two postmenopausal women of whom 14 were on hormone replacement therapy.

After an overnight fast, at 0800 hours on two nonconsecutive days, placebo or melatonin (1 mg) were administered randomly and in a double blind fashion. Forty‐five minutes later, an oral glucose tolerance test (75 g; OGTT) was performed in 13 women. In another nine women insulin‐dependent (Si) and ‐independent (Sg) glucose utilization was tested by a frequently sampled intravenous glucose tolerance test (FSIGT).

Areas under the response curve to OGTT (AUC) for glucose (1420 ± 59vs.1250 ± 55 mmol × min/l;P < 0·01), and C‐peptide (420980 ± 45320vs.33528 ± 15779 pmol × min/l;P < 0·02) were higher following melatonin than placebo, while Si values were lower (2·6 ± 0·28 unitsvs.3·49 ± 0·4 units;P < 0·03). Si modifications induced by melatonin were inversely related to Si values of the placebo day (r2 = 0·538;P < 0·025).

The present results indicate that in aged women administration of 1 mg of melatonin reduces glucose tolerance and insulin sensitivity. The present data may have both physiological and clinical implications.
The expression of thyrotrophin‐releasing hormone receptor 1 messenger ribonucleic acid in human pituitary adenomas
Authors: Kim Kyongsong , Arai Keiko , Sanno Naoko , Teramoto Akira , Shibasaki Tamotsu
Published: March 2003

Thyrotrophin‐releasing hormone (TRH) paradoxically induces the release of growth hormone (GH) when injected intravenously into acromegalic patients, although the mechanism of this action is unknown at present. Several research groups have reported that the level of TRH receptor‐1 (TRHR‐1) mRNA expression is variable in pituitary adenomas, and does not correlate with the degree of paradoxical GH response to TRH administration in a limited number of acromegalic patients. We aimed to compare the expression levels of TRHR‐1 mRNA among various types of pituitary adenoma and to clarify whether these levels correlate with the degree of pituitary hormone response to TRH.

Pituitary adenoma tissue was obtained by surgery from 14 patients with acromegaly, four with prolactinomas, nine with nonfunctioning adenomas and one with a TSH‐producing adenoma.

The level of human TRHR‐1 mRNA expression in each adenoma was quantified using the competitive reverse transcription polymerase chain reaction (RT‐PCR) method. For amplification of a TRHR‐1 cDNA fragment, a sense primer was designed according to the sequence in exon 2 and an antisense primer designed according to the sequence located at the region in exon 3 that does not encode for the alternative splicing‐generated short form of TRHR‐1 mRNA.

TRHR‐1 mRNA was detected in all pituitary adenomas examined and did not correlate with their size. The mean level of TRHR‐1 mRNA expression was significantly lower in GH‐producing adenomas than in prolactinomas and nonfunctioning adenomas (1·4 ± 0·4 × 10−2 attomol/μg total RNA, 10·7 3·4 × 10−2 attomol/μg total RNA, and 7·2 ± 3·3 × 10−2 attomol/g total RNA, respectively). The ratio of plasma peak GH induced by TRH administration to the basal level of plasma GH in the patients with acromegaly correlated positively with the level of TRHR‐1 mRNA expression in their GH‐producing adenomas (r = 0·620, P = 0·0179). The responsiveness of plasma PRL and gonadotrophin to TRH in the patients with prolactinoma and nonfunctioning pituitary adenoma did not significantly correlate with the levels of TRHR‐1 mRNA expression in their pituitary adenomas, respectively.

The findings of the present study suggest that the level of TRHR‐1 mRNA expression varies among different types of pituitary adenoma. Furthermore, in acromegaly, the responsiveness of plasma GH to TRH administration appears to at least partially depend on the level of TRHR‐1 mRNA expression in the GH‐producing pituitary adenoma.
Angiotensin II type 1 receptor and ACTH receptor expression in human adrenocortical neoplasms
Authors: Schubert Barbara , Fassnacht Martin , Beuschlein Felix , Zenkert Simone , Allolio Bruno , Reincke Martin
Published: March 2003

OBJECTIVE Type 1 angiotensin II (Ang II) receptors transduce most of the known actions of Ang II, including steroidogenesis and trophic actions on the adrenal cortex. We investigated the type 1 Ang II receptor expression in adrenocortical tissues to define its regulation in adrenocortical neoplasms and to compare its expression with that of the ACTH receptor (ACTH‐R).

PATIENTS AND MEASUREMENTS Poly A RNA was extracted from tumour tissue and electrophoresed through a 1·0% agarose gel, blotted and hybridized with α32P‐CTP labelled PCR generated type 1 Ang II receptor cDNA probe. Receptor autoradiography was performed on slices from normal adrenals and tumour tissue by incubation with 125I‐Sar1, Ile8‐Ang II with and without pretreatment with cold Ang II or with the selective type 1 receptor antagonist losartan.

RESULTS Ang II type 1 receptor mRNA was high in cortisol producing (CPA; n = 5) and aldosterone producing (APA; n = 4) adenomas (normal adrenals 100 ± 12% vs. 180 ± 16% in CPA and 154 ± 26% in APA, mean ± SEM), but was low in nonfunctioning adenomas (NFA; n = 2; 2 ± 1%). ACTH receptor mRNA followed a similar pattern (CPA 178 ± 17, APA 196 ± 30, NFA 0%, carcinomas 56 ± 11%) with a good correlation between Ang II type 1 receptor and ACTH‐R mRNA of r = 0·692, P = 0·0019. Receptor autoradiography in normal adrenals demonstrated Ang II type 1 receptors predominantly in the zona glomerulosa. In tumour tissue, mainly type 1 receptor expression was found confirming the Northern blot data.

CONCLUSIONS Angiotensin II type 1 receptor and ACTH receptor expression seems to be correlated with the functional status of adrenocortical tumours, suggesting regulation by similar factors. The predominant receptor expressed in adrenocortical tumours is the Angiotensin II type 1 receptor whereas type 2 receptor expression is minimal.
Polymorphic differences from normal in the aldosterone synthase gene (CYP11B2) in patients with primary hyperaldosteronism and adrenal tumour (Conn's syndrome)
Authors: Inglis Gordon C. , Plouin Pierre F. , Friel Elaine C. , Davies Eleanor , Fraser Robert , Connell John MC.
Published: March 2003

OBJECTIVE The hypertension of Conn's syndrome is due to autonomous aldosterone production by a unilateral adrenocortical adenoma. The source of tumour initiation and the reasons for excess aldosterone production as opposed to cortisol are not known, although variations in the promoter region of the gene coding for aldosterone synthase (CYP11B2) might account for the altered rate of aldosterone secretion.

DESIGN In a series (n = 27) of well–characterized Conn's syndrome cases, the aldosterone synthase gene (CYP11B2) was screened by single‐strand conformational polymorphism (SSCP) for differences from the consensus sequence.

RESULTS No new mutations were found. The frequencies of two previously described linked polymorphisms, one a change of −344C to T in a putative steroidogenic factor‐1 (SF‐1) binding site and the other an exchange of intron 2 for that of CYP11B1 (conversion) were measured in tumour and genomic DNA. The frequency of the SF‐1 T allele (P < 0·0001) and the conversion allele (P < 0·001) were markedly different between the Conn's syndrome group and the normal controls. However, the frequency did not differ between tumour and genomic DNA in the patient group.

CONCLUSION While it is unlikely that this difference from normal is related to tumour growth, these genotypes may predispose the tumour to aldosterone production.
Autoimmune thyroid syndrome in women with Turner's syndrome—the association with karyotype
Authors: Elsheikh M. , Wass J.A.H. , Conway G.S.
Published: March 2003

OBJECTIVE Females with Turner's syndrome (TS) are at an increased risk of developing autoimmune thyroid disease. Studies assessing the influence of karyotype on thyroid autoimmunity in adults with TS have yielded conflicting results but have been limited by small numbers. The aim of this study was to determine the frequency of thyroid autoimmunity in a large cohort of women with TS and to assess the influence of karyotype on the development of thyroid disease.

DESIGN, PATIENTS AND MEASUREMENTS Data were available for 145 women with TS attending a dedicated adult Turner clinic. The mean age was 26 years (range 16–52 years). Information regarding the presence of thyroid disease, karyotype, thyroid autoantibodies and thyroid function was recorded in all. The chi‐squared test with Yates' correction was used to assess the association between karyotype and thyroid autoimmunity.

RESULTS Forty‐one per cent of women with TS had positive thyroid autoantibodies and 16% of women were hypothyroid on replacement therapy with thyroxine. However, 83% of women with an X‐isochromosome had positive thyroid autoantibodies compared with 33% of women with other karyotypes (P < 0·0001). Women with an isochromosome‐X karyotype were also significantly more likely to become frankly hypothyroid and require thyroxine compared with other karyotypes (37·5% isochromosome‐X vs. 14% 45, X vs. 6% other karyotypes P = 0·0034).

CONCLUSIONS In this large cohort of women with TS we have shown that the risk of developing autoimmune thyroid disease is particularly high in women with an X‐isochromosome, suggesting that a gene on the long arm of the X chromosome (Xq) may play an important pathogenetic role in the development of autoimmune thyroid disease.
Sensitive LH and FSH assays for monitoring low serum levels in men undergoing steroidal contraception
Authors: Robertson David M. , Pruysers Enid , Stephenson Tanneale , Pettersson Kim , Morton Sue , McLachlan Robert I.
Published: March 2003

BACKGROUND AND OBJECTIVES Current immunoassays for detecting serum FSH and LH are not sufficiently sensitive to detect the markedly reduced levels in men undergoing steroidal hormonal treatment for contraceptive purposes. The purpose of this study was to increase the sensitivity of available LH and FSH immunofluorometric (Delfia®) assays in order to allow a better understanding of the importance of gonadotrophin suppression in achieving the optimal suppression of sperm count.

DESIGN AND PATIENTS Assay conditions were modified by increasing serum sample volume, the inclusion of either FSH‐ or LH‐depleted serum to reduce the resulting matrix effects and extending incubation times. The microassays were applied to serum from 10 men administered testosterone enanthate with or without depot medroxyprogesterone acetate for 12 weeks as part of a contraceptive trial.

RESULTS The assay sensitivities were increased to 0·005 IU/l for LH and 0·010 IU/l for FSH, representing a five‐ to six‐fold increase in sensitivity compared with existing assays. In the clinical trial, serum LH levels were suppressed to near or below the level of assay detection (mean 0·014 IU/l < 0·4% of pretreatment values) while in eight of 10 men, plasma FSH levels were detectable (0·04–0·07 IU/l, 1–5% of pretreatment values). These FSH levels would not have been detected by current assays.

CONCLUSIONS The increased sensitivities of the LH and FSH assays enabled the detection of gonadotrophins that were < 0·4% of pretreatment serum levels. Using these methods, serum LH was suppressed to nondetectable or near nondetectable levels while serum FSH was highly suppressed but still detectable in the majority of men undergoing steroidal treatment for contraceptive purposes.
Effects of fasting and pegvisomant on the GH‐releasing hormone and GH‐releasing peptide‐6 stimulated growth hormone secretion
Authors: Muller A. F. , Janssen J. A. M. J. L. , Lamberts S. W. J. , Bidlingmaier M. , Strasburger C. J. , Hofland L. , Van Der Lely A. J.
Published: March 2003

OBJECTIVE Pegvisomant is a mutated GH molecule which prevents functional dimerization and subsequent activation of the growth hormone receptor. Pegvisomant and fasting both lead to GH resistance.

DESIGN AND PATIENTS We performed a double‐blind placebo‐controlled cross‐over study comparing the effects of pegvisomant and fasting on the GH‐releasing hormone (GHRH)‐ and GH‐releasing peptide‐6 (GHRP‐6)‐stimulated GH‐release before and after 3 days of fasting in 10 healthy lean male subjects. We also performed a single‐arm open label study under nonfasting conditions in five of these subjects. On day 1, in random order, at 0800 h, a GHRP‐6 or GHRH test was performed. At 1600 h, a GHRH (if the first test was a GHRP‐6 test) or GHRP‐6‐test (if the first test was a GHRH test) was done. After the second test either pegvisomant (80 mg as a single subcutaneous injection) or placebo was administered. On day 4, GHRP‐6 and GHRH tests were performed in the same order as on day 1. During the cross‐over study, subjects fasted from 2400 h on day 1 until the end of the study.

MEASUREMENTS During the GH stimulation tests, blood samples were drawn every 15 min from 15 to 120 min. GH was determined in all samples. Total insulin‐like growth factor (IGF)‐I and free IGF‐I were determined from the samples at 0 min only.

RESULTS Three days of fasting alone and pegvisomant alone as well as in combination increased GH concentrations, whereas a decrease in serum‐free, but not total, IGF‐I concentrations was observed. On day 4, fasting and pegvisomant, either alone or in combination, significantly increased GH concentrations after GHRH compared to baseline. Pegvisomant alone did not increase GH concentrations after GHRP‐6 administration. Fasting alone increased GH levels after GHRP‐6 administration. The combination of fasting and pegvisomant had a synergistic effect on GH release after GHRP‐6.

CONCLUSION These human in vivo data suggest that: (1) circulating free IGF‐I, and not total IGF‐I, is the major component in the negative feedback on GH secretion; (2) increased pituitary GHRH receptor expression plays a role in the mechanism whereby fasting leads to increased GH concentrations; (3) in vivo, GHRP‐6 sensitivity seems to be regulated primarily by metabolic factors and not by changes in GH–IGF‐I axis.
Seasonal variation in glucocorticoid receptor binding characteristics in human mononuclear leucocytes
Authors: Blackhurst G. , McElroy P. K. , Fraser R. , Swan R. L. , Connell J. M. C.
Published: March 2003

OBJECTIVE Glucocorticoid sensitivity varies between individuals and between tissues in the same individual. Although some of this variation is explained by the activity of the 11β‐hydroxysteroid dehydrogenase enzymes, the possibility that glucocorticoid receptor sensitivity is modulated remains unexplored. This study examined glucocorticoid receptor binding in leucocytes and assessed the effects of seasonal hormonal variation on receptor binding.

PATIENTS AND MEASUREMENTS Two populations were studied. In the first, 318 healthy subjects were studied over 2 years with a single measurement of receptor binding made on each. In the second study nine healthy male subjects each had receptor binding measurements made at 3‐week intervals over 1 year.

RESULTS In both populations there was significant seasonal variation in receptor binding. In the first population Kd for dexamethasone was highest in November and lowest in July (8·37 ± 0·5 nmol/l vs. 1·58 ± 0·7, mean ± SEM P < 0·00001) and the number of receptor sites per leucocyte was highest in January and lowest in June (10 440 ± 580 vs. 4969 ± 302, P < 0·00001). In multivariate analysis, climate was the main determinant for both Kd and the number of receptor sites per cell: increases in day length and environmental temperature reduced Kd and the number of receptor sites per cell. Co‐incubation with physiological concentrations of melatonin raised Kd without affecting receptor number. Co‐incubation with forskolin lowered Kd suggesting that melatonin might act through the ML1 receptor class by inhibiting adenylyl cyclase. No correlations were found with 0900 h plasma cortisol.

CONCLUSIONS The results suggest that the glucocorticoid receptor might be modulated by season. Melatonin might mediate part of these effects. The lack of correlation with cortisol suggests that it is not an important determinant of receptor binding and that leucocyte receptors are regulated differently from central receptors.
Polycystic ovary syndrome after precocious pubarche: ontogeny of the low‐birthweight effect
Authors: Ibáñez Lourdes , Valls Carme , Potau Neus , Marcos Maria Victoria , De Zegher Francis
Published: March 2003

OBJECTIVE Young girls with precocious pubarche (PP) are at increased risk of developing polycystic ovary syndrome (PCOS), including hyperinsulinism, dyslipidaemia and ovarian hyperandrogenism, particularly if PP itself was preceded by a low birthweight. Resistance to insulin is thought to be a key factor in the pathogenesis of this sequence. We aimed to elucidate the peripubertal ontogeny of the low birthweight effect on hyperinsulinism, dyslipidaemia and ovarian dysfunction after PP.

PATIENTS AND DESIGN We obtained fully longitudinal data from 51 girls with a history of PP and compared normal‐birthweight (n = 26) with low‐birthweight (n = 25) girls (birthweight SD score 0·0 ± 0·2 vs. − 2·4 ± 0·2) for measurements obtained at diagnosis of PP (mean age 7·0 years), in early puberty (10·4 years) and after menarche (14·3 years).

MEASUREMENTS Fasting serum lipids and lipoproteins, together with insulin responses to an oral glucose load, were assessed at diagnosis of PP, in early puberty and after menarche; serum gonadotropins were measured in early puberty and after menarche; ovarian function was examined postmenarche.

RESULTS Comparisons of endocrine‐metabolic results between normal‐ and low‐birthweight PP girls showed no detectable differences before puberty. The hypertriglyceridaemia and elevated LDL‐cholesterol levels characterizing low‐birthweight PP girls became detectable by early puberty; reduced insulin sensitivity was not evident until postmenarche, when the tendency to ovarian dysfunction also became obvious. Body mass indices of normal‐ and low‐birthweight subgroups were identical in early puberty and postmenarche.

CONCLUSIONS These longitudinal data show that, in PP girls, the endocrine‐metabolic risk conferred by prenatal growth restraint is not readily detectable until puberty or postmenarche, and is not attributable to a higher body mass index.
Lack of influence of the androgen receptor gene CAG‐repeat polymorphism on sex steroid status and bone metabolism in elderly men
Authors: Van Pottelbergh I. , Lumbroso S. , Goemaere S. , Sultan C. , Kaufman J. M.
Published: March 2003

OBJECTIVEPopulation means for serum testosterone (T) levels in healthy men decrease with ageing but there is considerable interindividual variability of serum T in elderly men. Ultimate androgen action is mediated through the androgen receptor. Subtle differences in androgen sensitivity might contribute to serum T variability through the T negative feedback regulation. The androgen receptor gene (AR) contains in exon 1 a polymorphic trinucleotide CAG‐repeat, whose length modulates androgen receptor action. The aims of the study were to assess the potential contribution of the AR CAG‐repeat polymorphism in the interindividual variability of serum T and in the determination of bone metabolism in ambulatory elderly men.

DESIGN AND PATIENTSWe used cross‐sectional baseline data of a longitudinal study investigating the process of ageing, in particular the changes in hormonal status and bone metabolism, in a cohort of 273 community‐dwelling healthy men, between age 71 and 86 years.

MEASUREMENTSAR CAG‐repeat length was determined by automated DNA sequencing of exon 1 of the AR gene. Serum T, sex hormone binding globulin, LH and oestradiol were measured by specific immunoassays. Bone mineral density (BMD) was determined by dual energy X‐ray absorptiometry. Bone turnover was assessed by measurement of serum bone‐specific alkaline phosphatase, serum osteocalcin, serum C‐terminal type I procollagen peptide, serum and urinary C‐terminal telopeptides of type I collagen and urinary deoxypyridinoline levels, with use of immunoassays.

RESULTSNo significant association was found between the AR CAG‐repeat length and either total or free T, LH or the androgen sensitivity index (LHxT). BMD measurements at the hip and the forearm were not associated with AR CAG‐repeat length and there was no association of this AR polymorphism with any of the biochemical markers of bone turnover. Results were not different after adjustments for age and body mass index.

CONCLUSIONSThe findings of the present study do not support the view that in community‐dwelling, healthy elderly men the androgen receptor gene CAG‐repeat polymorphism has a substantial impact on interindividual variability of serum testosterone levels or on the determination of bone turnover and bone mineral density.