Europium as a label in time-resolved immunofluorometric assays

Hemmilä, Ilkka; Dakubu, S.; Mukkala, Veli-Matti; Siitari, Harri; Lövgren, Timo

doi:10.1016/0003-2697(84)90095-2

Cited by 829 publications

(480 citation statements)

References 24 publications

Supporting

Mentioning

466

Contrasting

Unclassified

Order By: Relevance

“…Muscle biopsies were obtained from the vastus lateralis muscle under local anaesthesia during both basal and insulin-stimulated states. Plasma glucose and insulin concentrations and specific activity of 3 H 2 O were measured as previously described [17,24,25].…”

Section: Clinical Examination and Muscle Biopsies In Twinsmentioning

confidence: 99%

Age influences DNA methylation and gene expression of COX7A1 in human skeletal muscle

et al. 2008

View full text Add to dashboard Cite

Aims/hypothesis Reduced oxidative capacity of the mitochondria in skeletal muscle has been suggested to contribute to insulin resistance and type 2 diabetes. Moreover, a set of genes influencing oxidative phosphorylation (OXPHOS) is downregulated in diabetic muscle. Here we studied whether genetic, epigenetic and non-genetic factors influence a component of the respiratory chain, COX7A1, previously shown to be downregulated in skeletal muscle from patients with type 2 diabetes. The specific aims were to: (1) evaluate the impact of genetic (single nucleotide polymorphisms [SNPs]), epigenetic (DNA methylation) and non-genetic (age) factors on the expression of COX7A1 in human skeletal muscle; and (2) investigate whether common variants in the COX7A1 gene are associated with increased risk of type 2 diabetes. Methods COX7A1 mRNA expression was analysed in muscle biopsies from young (n=110) and elderly (n=86) non-diabetic twins and related to measures of in vivo metabolism. Genetic variants (three SNPs) from the COX7A1 locus were genotyped in the twins and in two independent type 2 diabetes case-control cohorts (n=1466 and 6380, respectively). DNA methylation of the COX7A1 promoter was analysed in a subset of twins (ten young, ten elderly) using bisulphite sequencing. Results While DNA methylation of the COX7A1 promoter was increased in muscle from elderly compared with young twins (19.9±8.3% vs 1.8±2.7%; p=0.035), the opposite was found for COX7A1 mRNA expression (elderly 1.00±0.05 vs young 1.68 ± 0.06; p = 0.0005). The heritability of COX7A1 expression was estimated to be 50% in young and 72% in elderly twins. One of the polymorphisms investigated, rs753420, influenced basal COX7A1 expression in muscle of young (p=0.0001) but not of elderly twins. The transcript level of COX7A1 was associated with increased in vivo glucose uptake and V : O 2max (p=0.009 and p=0.001, respectively). We did not observe any genetic association between COX7A1 polymorphisms and type 2 diabetes after correcting for multiple testing. Diabetologia (2008) Conclusions/interpretation Our results provide further evidence for age as a factor influencing DNA methylation and expression of OXPHOS genes, and thereby in vivo metabolism.

show abstract

Section: Clinical Examination and Muscle Biopsies In Twinsmentioning

confidence: 99%

Age influences DNA methylation and gene expression of COX7A1 in human skeletal muscle

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Using both spectral and temporal discrimination of the luminescent signal from background autofluorescence enables highly sensitive assays, 5,6 such as the Dissociation Enhanced Lanthanide Fluoro Immuno Assay (DELFIA ® ) techniques first commercialized by Wallac ™ , which use a polyaminocarboxylate chelate of Eu(III). 7 However, the DELFIA ® format is heterogeneous and suffers from the limitation that the fluorescent signal cannot be traced until the end of the assay, when the non-fluorescent Ln(III) chelate is converted to a highly fluorescent form by the addition of a sensitizing -diketonate enhancement solution. Hence, the preparation of efficient lanthanide sensitizers which also form very stable complexes in dilute aqueous solution is an active area of research, since they can be utilized directly and/or covalently bound to a particular biomolecule for use in a less expensive and less time consuming homogenous assays formats.…”

Section: Introductionmentioning

confidence: 99%

Highly Luminescent Lanthanide Complexes of 1-Hydroxy-2-pyridinones

et al. 2008

View full text Add to dashboard Cite

The synthesis, X-ray structure, stability, and photophysical properties of several trivalent lanthanide complexes formed from two differing bis-bidentate ligands incorporating either alkyl or alkyl ether linkages and featuring the 1-hydroxy-2-pyridinone (1,2-HOPO) chelate group in complex with Eu(III), Sm(III) and Gd(III) are reported. The Eu(III) complexes are among some of the best examples, pairing highly efficient emission ( Eu tot Φ ~ 21.5 %,) with high stability (pEu ~ 18.6) in aqueous solution, and are excellent candidates for use in biological assays. A comparison of the observed behavior of the complexes with differing backbone linkages shows remarkable similarities, both in stability and photophysical properties. Low temperature photophysical measurements for a Gd(III) complex were also used to gain insight into the electronic structure, and were found to agree with corresponding TD-DFT calculations for a model complex. A comparison of the high resolution Eu(III) emission spectra in solution and from single crystals also revealed a more symmetric coordination geometry about the metal ion in solution due to dynamic rotation of the observed solid state structure.

show abstract

“…In a blood glucose range of 4 to 10 mmol/l intra-assay coefficient of variation (CV) was 2.0% and interassay CV was 2.2%. Serum insulin concentrations were measured using a two-site, two-step, time-resolved immunofluorometric assay (DELFIA, Turku, Finland) [15]. Cross-reactivities with proinsulin, C-peptide and Des(31,32)-split product in the insulin assay were all less than 0.4%.…”

mentioning

confidence: 99%

Twin study of genetic and environmental influences on glucose tolerance and indices of insulin sensitivity and secretion

et al. 2003

View full text Add to dashboard Cite

Aims/hypothesis. Family and twin studies have reported different estimates of the relative contribution of genetic and environmental factors to the quantitative traits glucose tolerance, insulin secretion, and insulin sensitivity. Our aims were to estimate these relative influences in a large sample of twins from the population and to assess the effect of age. Methods. In this population-based, cross-sectional study we gave an oral glucose tolerance test to 317 women and 290 men who were same-sex healthy twin pairs between 18 to 67 years of age. The genetic, common environmental and individual environmental variance components for fasting and 120-min glucose and for fasting and 30-min insulin as well as the linear effects of age on these components were estimated by multivariate analysis (using the software FISHER). Results. In women and men the heritability for fasting glucose was 12 and 38%, for 120-min glucose it was 38 and 43%, for fasting insulin it was 54 and 37%, and for 30-min insulin it was 57 and 47%, respectively. Under the assumption of no non-additive genetic effects (no intra-or inter-gene interaction) there was no strong evidence for common environmental effects, barring significant effects for fasting glucose in women. Heritability decreased with age for 120-min glucose in women and fasting insulin in men, whereas it increased for 120-min glucose in men. Conclusion/interpretation. This study indicates a limited additive genetic influence on the result of an OGTT, possibly with sex-specific age effects, and generally little or no influence of the common environment. Accordingly, there is a considerable individual environmental variation. [Diabetologia (2003[Diabetologia ( ) 46:1276[Diabetologia ( -1283

show abstract

Europium as a label in time-resolved immunofluorometric assays

Cited by 829 publications

References 24 publications

Age influences DNA methylation and gene expression of COX7A1 in human skeletal muscle

Age influences DNA methylation and gene expression of COX7A1 in human skeletal muscle

Highly Luminescent Lanthanide Complexes of 1-Hydroxy-2-pyridinones

Twin study of genetic and environmental influences on glucose tolerance and indices of insulin sensitivity and secretion

Contact Info

Product

Resources

About