Effect of topiramate on cognition in obese children.
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Biomedical subjects
Publications and source records attributed to Erica L T van den Akker.
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The aim of this study was to determine whether polymorphisms of the glucocorticoid receptor gene, influencing glucocorticoid sensitivity, are associated with persistent nasal carriage of Staphylococcus aureus. Two nasal swab cultures were obtained from each of 2,929 participants. Subjects were classified as persistent carriers (n=563) if both cultures were positive. GG homozygotes of the exon 9beta polymorphism were associated with a 68% reduced risk of persistent S. aureus nasal carriage, whereas carriers of the codon 23 lysine allele displayed an 80% increased risk. Thus, genotype-dependent variation in the sensitivity to glucocorticoids is associated with tolerance toward staphylococcal nasal colonization.
CONTEXT: Glucocorticoids (GCs) are extensively used in the treatment of inflammatory and autoimmune diseases. Their beneficial effects are thought to be mediated by GC transrepression on gene expression. However, their use is limited by serious adverse effects, presumably mediated by GC transactivation of gene expression. OBJECTIVE: The objective of the study was to investigate the effect of the GC receptor haplotype, characterized by the GR-9beta polymorphism, on GC transactivation and transrepression. DESIGN AND METHODS: This was a cross-sectional study in 216 persons randomly selected from participants in The Rotterdam Study, a population-based cohort study in the elderly. Clinical and biochemical parameters of GC sensitivity were measured: weight, height, waist to hip ratio, glucose, insulin, total cholesterol, high-density lipoprotein, and C-reactive protein. In a dexamethasone suppression test, the response of serum cortisol concentrations was studied. Genotyping for four GC receptor polymorphisms was performed. In addition, ex vivo experiments were performed with leukocytes of 10 healthy controls and two persons homozygous for the GR-9beta polymorphism, in which the expression of two GC-sensitive genes, GC-induced leucine zipper and IL-2, was measured. RESULTS: Persons carrying the GR-9beta haplotype without 22/23EK (n = 53) revealed no significant differences in their body mass index, waist to hip ratio, fat spectrum, and insulin sensitivity or in their cortisol response to dexamethasone and levels of C-reactive protein, compared with noncarriers (n = 113). Ex vivo, GC-induced up-regulation of GC-induced leucine zipper mRNA via transactivation did not significantly differ in GR-9beta homozygotes, whereas the down-regulation of IL-2 expression via transrepression was decreased. CONCLUSION: Persons carrying the GR-9beta haplotype seem to have a decreased GC transrepression with normal transactivation.
CONTEXT: The clinical presentation of abnormalities in glucocorticoid (GC) sensitivity is diverse, and therefore it is difficult to diagnose this condition. OBJECTIVE AND DESIGN: The objective of the study was to develop strategies for the characterization of GC sensitivity disorders. SETTING: The study was conducted in an outpatient clinic. PATIENTS: Nine patients with GC sensitivity disorders participated. INTERVENTIONS: Sequence analysis of the GC receptor (GR), determination of GR number per cell, GR ligand-binding affinity, and GR splice regulation were performed in freshly prepared peripheral blood mononuclear lymphocytes and Epstein-Barr virus-transformed lymphoblasts. Cellular GC sensitivity was determined ex vivo by measuring the effect of dexamethasone on GC-induced leucine-zipper and IL-2 mRNA levels and on cell proliferation. RESULTS: Differences in GR number per cell, GR affinity, GR splice variants, and effects on transactivation or transrepression of GC-sensitive genes were observed between patients and controls. Epstein-Barr virus transformation of lymphoblasts had no influence on GR affinity but increased the GR number 5-fold in healthy controls. In patients diagnosed as cortisol resistant, however, GR number after transformation was increased significantly less than 5-fold, whereas a higher GR number was observed in a patient suspected of cortisol hypersensitivity. CONCLUSION: This study illustrates several strategies to define abnormalities in GC sensitivity by describing nine patients with affected GC sensitivity, all with a unique clinical course and background.
CONTEXT: Interindividual variation in glucocorticoid (GC)-sensitivity can be partly explained by polymorphisms in the GC receptor (GR) gene. The ER22/23EK and N363S polymorphisms have been described to be associated with lower and higher GC sensitivity, respectively. OBJECTIVE AND DESIGN: We examined the basis of this altered GC sensitivity by expressing GR(N363S) and GR(ER22/23EK) in COS-1 cells and investigating their transactivating and transrepressing capacities using a GC response element-luciferase reporter and a p65-activated nuclear factor kappaB-luciferase reporter, respectively. Furthermore, we evaluated the transactivating and transrepressing capacities of the GR in peripheral blood mononuclear lymphocytes of homozygous and heterozygous carriers of these polymorphisms by determining the maximum effect of dexamethasone on transactivation of the GC-induced leucine-zipper and transinhibition of the IL-2 gene by means of real-time RT-PCR. RESULTS: The effects of the polymorphisms in the GR gene previously observed in population studies were also detected at the level of gene expression. The ER22/23EK polymorphism resulted in a significant reduction of transactivating capacity, in both transfection experiments (-14 +/- 5%, P < 0.05) and peripheral blood mononuclear lymphocytes of carriers of this polymorphism (homozygous: -48 +/- 6%, P < 0.01, n = 1; heterozygous: -21 +/- 4%, P = 0.08, n = 3). The N363S polymorphism, associated with increased GC sensitivity, resulted in a significantly increased transactivating capacity, both in vitro (8 +/- 3%; P < 0.02) and ex vivo (homozygous: 204 +/- 19%, P < 0.0001, n = 1; heterozygous: 124 +/- 8%, P = 0.05, n = 3). Neither the ER22/23EK nor the N363S polymorphism seemed to influence the transrepressing capacity of the GR. CONCLUSION: The presence of these and other GC sensitivity-modulating polymorphisms may have consequences for the use of GCs in a clinical setting.
UNLABELLED: We describe a 19-year-old female, known to have congenital hemihypertrophy, who presented with bilateral benign pheochromocytoma. This is the second time that this combination has been reported in the literature. We speculate that the combination of congenital hemihypertrophy and pheochromocytoma is not coincidental and could be part of the clinical spectrum of the Beckwith-Wiedemann syndrome. CONCLUSION: in patients with congenital hemihypertrophy, the physician should be aware of the symptoms of pheochromocytoma. Besides screening for abdominal tumours, analysis of plasma and/or urinary catecholamines and/or their metabolites should be considered.