No direct effect of the -521 C/T polymorphism in the human dopamine D4 receptor gene promoter on transcriptional activity

BACKGROUND: The human dopamine D4 receptor (DRD4) gene has been studied extensively as a candidate gene for certain psychological traits and several behavioural and psychiatric disorders. Both the 5' regulatory region and the coding sequence contain a number of polymorphisms. The promoter variants have received particular attention in the past few years due to their possible role in the regulation of gene transcription. Previously, the -521C/T SNP was shown to influence promoter activity. The aim of this study is to perform an in-depth analysis of this effect in the context of various neural cell lines. RESULTS: Endogenous mRNA expression of the DRD4 gene was demonstrated in two neuroblastoma (SK-N-F1, IMR32) and one retinoblastoma cell line (Y79) by RT-PCR. In addition, very low DRD4 mRNA levels were also detected in HeLa cells. The transcriptional activity of a series of 5' promoter deletion mutants was determined by transient transfection of luciferase reporter constructs. The activity profile of these promoter fragments was similar in each of the cell lines tested. The highest luciferase reporter activity was obtained with a construct containing promoter sequences between nucleotides -668 to -389, while a putative silencer region was localised spanning from nucleotide -1571 to -800. Surprisingly, the -521 C/T polymorphism had no significant effect on transcriptional activity of the reporter construct with the highest activity (-668 to -389) in any of the three cell lines tested. CONCLUSION: Our results do not confirm previous data assigning different transcriptional activities to the -521 C/T alleles of the human DRD4 promoter. Furthermore, these findings highlight the need for further characterization of the 5' regulatory region of the DRD4 gene and identification of additional functional promoter polymorphic sites, especially in the context of haplotype

Determination of Nonylphenol Polyethoxylates and Their Lipophilic Metabolites in Sewage Effluents by Normal-phase High-performance Liquid Chromatography and Fluorescence Detection

Analytical procedures using normal-phase high-performance liquid chromatography (HPLC) with fluorescence detection, suitable for the routine determination of alkylphenol polyethoxylate (APnEO) surfactants and their lipophilic metabolites in sewage effluents at sub-microgram per litre level, have been developed. The parent nonylphenol polyethoxylates (NPnEO), covering oligomer range of 1-18 ethoxy units per molecule, were extracted from water sam-ples using solid-phase extraction on graphitised carbon black (GCB), while their lipophilic metabolites, including nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO) and nonylphenol (NP), were extracted by liquid-liquid extraction into n-hexane. The extracts were analysed by normal-phase HPLC using amino-silica columns and fluorescence detection at 228/305 nm. This allowed reliable quantitative determination of individual oligomers down to 0.1 μg/l. Analyses of sewage effluents collected in several sewage treatment plants of the Canton of Zürich, Switzerland, indicated that NPnEO occur at significant concentrations (96-430 μg/l) despite the partial ban introduced in 1986. Oligomer distributions found in analysed sewage samples revealed that the major part of toxic lipophilic metabolites, including NP, still originate from detergent-derived NPnEO

The Fate of Organic Pollutants in Wastewater and Sludge Treatment: Significant Processes and Impact of Compound Properties

The fate of organic pollutants during wastewater and sludge treatment is determined by three main processes: gas exchange, sorption to suspended solids, and biodegradation. The influence of these processes differs strongly depending on the physicochemical properties of the individual compound and the particular treatment stage. For the assessment of the fate of trace pollutants in wastewater treatment, the impact of these processes must be evaluated. An acceptable removal in mechanical-biological wastewater treatment is achieved for hydrophilic compounds if they are rapidly degradable under aerobic conditions. Substances with lipophilic or amphiphilic properties should be degradable under aerobic and anaerobic conditions in order to prevent accumulation in digested sewage sludges. This article presents recent and current investigations at EAWAG which deal with the fate of selected organic substances in municipal wastewater and sludge treatment

Reference values for leptin and adiponectin in children below the age of 10 based on the IDEFICS cohort

OBJECTIVE: To establish age- and sex-specific reference values for serum leptin and adiponectin in normal-weight 3.0-8.9-year old European children. SUBJECTS AND METHODS: Blood samples for hormone analysis were taken from 1338 children of the IDEFICS (Identification and prevention of Dietary-and lifestyle-induced health Effects in Children and infantS) study cohort. Only normal-weight children aged 3.0-8.9 years were included (n = 539) in our analysis. Using the General Additive Model for Location Scale and Shape, age-and sex-specific percentiles were derived. The influence of under/overweight and obesity on the proposed reference curves based on normal-weight children was investigated in several sensitivity analyses using the sample without obese children (n = 1015) and the whole study sample (n = 1338). RESULTS: There was a negative age trend of adiponectin blood levels and a positive trend of leptin levels in boys and girls. Percentiles derived for girls were generally higher than those obtained for boys. The corresponding age-specific differences of the 97th percentile ranged from -2.2 to 4.6 mu g ml(-1) and from 2.2 to 4.8 ng ml(-1) for adiponectin and leptin, respectively. CONCLUSIONS: According to our knowledge, these are the first reference values of leptin and adiponectin in prepubertal, normal-weight children. The presented adiponectin and leptin reference curves may allow for a more differentiated interpretation of children's hormone levels in epidemiological and clinical studies