Hormone research最新文献

Heterozygous germline mutations in the gene encoding the aryl hydrocarbon receptor-interacting protein (AIP) were first described in two Finnish families with pituitary adenomas. The gene is involved in about 15% of familial isolated pituitary adenomas (FIPA), in about 50% of cases of familial acromegaly and in a small proportion of acromegalic patients with sporadic presentation. This review describes the genetic and clinical features of published patients with AIP, with either familial or sporadic pituitary tumors. A genotype-phenotype correlation is proposed: patients with AIP mutations resulting in a truncated protein are significantly younger than those bearing a mutation which preserves the structure of the C-terminal end of the protein (22.7 +/- 9.6 vs. 29.8 +/- 10.9 years). Pituitary tumors linked to AIP mutations are almost exclusively somatotropic (87.5%, n = 56/64) or lactotropic (9.4%, n = 6). Patients with AIP mutations are mostly men (70%, 44 M/19 F), suffer macroadenomas (97%) and are younger at diagnosis (24.4 +/- 10.5 years) than unselected patients with pituitary tumors. Thus, AIP is involved in the development of pituitary tumors, especially involving the somatomammotroph lineage. Genetic testing could be discussed for FIPAs and in young acromegalic patients with a sporadic presentation. Functional studies are needed to understand AIP-induced tumorigenesis.

The involvement of coactivators and corepressors, collectively termed as coregulators, increases the complexity of regulation of steroid hormone action. Following the interaction of the steroid hormone-receptor complex with the specific nucleotide sequences of target genes, the coregulators are recruited for activation or suppression of specific genes. The coregulators regulate a number of hormonal events during pregnancy, sex differentiation, development, reproduction and sexual behavior. They also exert equally important functions in non-reproductive tissues like heart, kidney, pancreas, bone and brain. The mutation and/or aberrant expression of these coregulators affect the normal function of steroid hormones and result in physiological abnormalities leading to the development of diseases. Therefore, understanding the role of coregulators in steroid hormone action is important and would help in developing the therapeutic strategy for the treatment of steroid-related diseases. In this review article, we describe the coregulators and their implication in health and pathogenesis of diseases. Furthermore, the possible therapeutic approach has been discussed for the treatment of steroid-related diseases, which will be of future interest in the field of medical sciences.

Background/aims: The aim of the study was to evaluate the efficacy and safety of lanreotide prolonged release (PR) 30 mg (long-acting lanreotide) in girls with constitutional tall stature (CTS).

Methods: This open label prospective study included 35 girls (mean age 12.6 years) with CTS and a predicted adult height of >180 cm. Intramuscular injections of lanreotide PR 30 mg were given every 14 days, for a minimum of 12 months and up to 36 months. Adult height was compared with pretreatment predicted height.

Results: The mean predicted adult height was reduced by 3.8 cm (95% CI 3.7-4.9 cm) in the restricted intent-to-treat population. Mean growth velocity decreased from 7.9 +/- 1.5 cm/year at preinclusion to 1.7 +/- 2.3 cm/year at the last visit on treatment (n = 35). Gastrointestinal adverse events and cholelithiasis were reported in 35/37 patients and 5/37 patients, respectively. There was 1 withdrawal due to gastrointestinal disorders.

Conclusions: Biweekly intramuscular lanreotide PR 30 mg given to girls with CTS after the onset of pubertal development reduced adult height as compared with predicted height. Treatment-associated adverse events were consistent with the overall safety profile of lanreotide 30 mg PR and did not deter most patients from long-term treatment.

Background/aims: The link between abdominal fat and bone mineral content (BMC), independent of weight, has not been extensively studied. In Latino children, the contributions of abdominal subcutaneous and visceral fat to BMC have not been examined. Research on the effect of leptin on BMC has also been inconclusive.

Methods: The present study included 256 overweight Latino children (111 girls, 145 boys; mean BMI 28.2; age 11.1 +/- 1.7 years) from Los Angeles, California. Subcutaneous abdominal adipose tissue (SAAT) and intra-abdominal adipose tissue (IAAT) were determined by single-slice magnetic resonance imaging. BMC was measured using dual-energy X-ray absorptiometry.

Results: Independent of age, Tanner stage and weight, abdominal adipose tissue (SAAT + IAAT) was inversely correlated with BMC (r = -0.46, p < 0.0001; n = 256). In girls, there was an inverse correlation between SAAT and BMC (r = -0.38, p < 0.05), between IAAT and BMC (r = -0.32, p < 0.05) and between leptin and BMC (r = -0.39, p < 0.05). In boys, SAAT and BMC were inversely correlated (r = -0.26, p < 0.05), but the correlation between IAAT and BMC was not significant (p = 0.22). Leptin was also inversely correlated with BMC (r = -0.38, p < 0.05) in boys and contributed to the variances in BMC in both girls and boys.

Conclusion: Total abdominal adipose fat and leptin are negatively associated with BMC in Latino children. The correlation between SAAT and BMC is stronger in girls than boys. IAAT and BMC are negatively associated in girls but not correlated in boys.

Aims: We compared the phenotype of adolescents with Klinefelter syndrome diagnosed by amniocentesis or postnatally to the general population with a view to evidence-based genetic counselling.

Methods: The charts of 28 patients seen between ages 12 and 18 years were reviewed. Physical and neurodevelopmental data were compared between patients diagnosed by chance (amniocentesis, group A, n = 11) or on the basis of symptoms (group B, n = 17) and the general population. Our hypothesis was that group A would have a more heterogeneous and less severe phenotype than group B.

Results: All patients had spontaneous puberty. The 2 patient groups were similar in physical development. Mean testosteronemia became lower than the normal mean from age 14 years. Compared to the general population, the prevalence of gynecomastia and school delay in group A was not significantly different (gynecomastia 33 vs. 40%, p = 0.70; school delay 40 vs. 20%, p = 0.25). In contrast, gynecomastia (77%) and school delay (56%) were significantly more frequent in group B than in the general population (p = 0.01 for both).

Conclusions: Although they are based on a small number of patients, our data provide the groundwork for cautious optimism in prenatal counselling for Klinefelter syndrome.

Purpose: To assess the effect of growth hormone (GH) treatment on body composition and insulin resistance, and the interdependence of these factors, in short children born small for gestational age (SGA) and children with growth hormone deficiency (GHD).

Methods: In this longitudinal study we describe the relationship between changes in fasting hormone levels, and forearm cross-sectional fat/muscle area in 54 short children with GHD and 37 short children born SGA during the first 12 months of GH treatment. Mean GH dose was 31.4 microg/kg/day for GHD and 53.2 microg/kg/day for SGA. HOMA2-IR was calculated as a steady-state fasting measure of insulin resistance.

Results: At baseline the SGA group displayed higher fasting glucose, insulin, C-peptide serum levels and higher HOMA2-IR (p < 0.01) than GHD patients despite similar low muscle mass and less fat mass. Both groups had low muscle mass for height, and mean changes in muscle, fat, insulin, C-peptide and HOMA2-IR during GH treatment were also similar. HOMA2-IR correlated positively with IGF-1 changes in both groups. In the SGA group, but not in the GHD group, the increase in fasting serum insulin, C-peptide and HOMA2-IR correlated negatively with increase in muscle mass (R(2) = 0.32, p < 0.001) and decrease in fat mass (R(2) = 0.12, p = 0.034).

Conclusions: In SGA, unlike in GHD, the insulin resistance caused by GH treatment appears to be diminished by the GH-induced increase in muscle mass and decrease in fat mass.

Pseudohypoaldosteronism (PHA) is a rare heterogeneous syndrome of mineralocorticoid resistance causing insufficient potassium and hydrogen secretion. PHA type 1 (PHA1) causes neonatal salt loss, failure to thrive, dehydration and circulatory shock. Two different forms of PHA1 can be distinguished on the clinical and genetic level, showing either a systemic or a renal form of mineralocorticoid resistance. This review provides an overview on transepithelial sodium reabsorption and on clinical features and the underlying molecular pathology of systemic and renal PHA1 caused by mutations in the subunit genes (SCNN1A, SCNN1B, SCNN1G) of the epithelial sodium channel (ENaC) and the mineralocorticoid receptor coding gene NR3C2. The in vitro investigation of several mutants has resulted in important progress in the understanding of the physiology of ENaC and the mineralocorticoid receptor. Some mutations are discussed in more detail to demonstrate some of these findings. A better clinical work-up of the patients suffering from PHA1 may delineate additional associations between the genotype and phenotype in the future.

Background/aims: Visfatin is a recently discovered adipokine, and its circulating concentrations have not been adequately studied in type 1 diabetes mellitus (DM). Therefore, this study was designed to examine plasma visfatin levels in type 1 diabetic patients and to determine the relationships between visfatin and duration of diabetes, body mass index, glycemic control, insulin dosage and lipid profile.

Methods: Forty-eight patients with type 1 DM and 26 healthy controls were investigated.

Results: Type 1 diabetic patients had significantly low visfatin levels compared with controls (18.8 +/- 1.7 vs. 20.2 +/- 0.3 ng/ml; p < 0.0001). Visfatin levels were comparable between patients with a short duration of diabetes (<10 years) and patients with a long duration of diabetes (>or=10 years) (18.9 +/- 1.7 vs. 18.2 +/- 2.0 ng/ml; p > 0.05). There was a significant correlation between visfatin and hemoglobin A1c (HbA1c) even after the adjustment for age, sex, body mass index and duration of diabetes (r = -0.48, p = 0.005) in the patient group. Multivariate analysis showed that significant determinants of visfatin concentrations were HbA1c and duration of diabetes (r(2) = 0.27).

Conclusion: These data emphasize that plasma visfatin concentrations are lower in patients with type 1 DM and related to glycemic control reflected by HbA1c.

Graves' disease is the most common cause of hyperthyroidism in children. Antithyroid drug (ATD) treatment is recommended as the initial treatment, leading to a marked improvement in most symptoms within 1 month of treatment initiation. Remission is achieved in 30% of children after a first course of ATD. Alternative treatments, such as radioactive iodine or thyroidectomy, are considered in cases of relapse, lack of compliance or ATD toxicity. The risk of relapse after a first course of ATD treatment for a median period of 2 years has been shown to be higher in patients with severe biochemical hyperthyroidism at diagnosis, young children and patients of non-Caucasian origin. Relapse risk decreases with the duration of the first course of ATD treatment, highlighting the positive impact of a long period of primary ATD treatment on outcome. The identification of predictive factors has made it possible to stratify patients according to the risk of relapse after ATD treatment, leading to improvements in patient management by facilitating the identification of patients requiring long-term ATD or early alternative therapy. Long-term careful follow-up is needed to determine the efficacy of disease management during childhood.