Search results for "competitive"
showing 10 items of 720 documents
Organochromium complexes - labelled aminoglycoside antibiotics derived from kanamycin A and tobramycin. Synthesis, structural characterization and us…
1993
Abstract The synthesis of metallocenic derivatives of aminoglycoside antibiotics, i. e. kanamycin A and tobramycin, is described. The organometallic-labelled compounds have been obtained from the reaction between the polyaminodrugs and organochromium esters of N-hydroxysuccinimide. The reaction proceeded selectively at the 6′-N position, as might be deduced both from the mass and the pH-dependent 13 C-NMR spectra. The procedure could be regarded as generally useful for the metallolabelling of aminoglycoside antibiotics. As an example of application a competitive immunoassay based on the use of these labels is proposed.
Optical biosensor-based characterization of anti-double-stranded DNA monoclonal antibodies as possible new standards for laboratory tests.
2009
The serum determination of circulating anti-double-stranded (ds)DNA autoantibodies is a routine measure for the laboratory diagnosis of systemic lupus erythematosus. Since available assays differ substantially and no feasible calibrator is available, the aim of this study was to evaluate a recently introduced surface plasmon resonance (SPR) biosensor chip for binding studies between dsDNA and anti-dsDNA autoantibodies and to demonstrate its usefulness for the characterization of new monoclonal antibody (mAb) standards and standardization of assays. We characterized two human and one murine monoclonal anti-dsDNA antibodies by measuring the kinetic on- and off-rates using the biosensor and ca…
Generation of anti-azoxystrobin monoclonal antibodies from regioisomeric haptens functionalized at selected sites and development of indirect competi…
2012
Azoxystrobin is a modern strobilurin fungicide used around the world to combat prime diseases affecting highly valuable crops. Accordingly, residues of this chemical are frequently found in food, even though mostly under maximum tolerated levels. We herein describe the development of an indirect competitive immunoassay for the determination of azoxystrobin residues. A panel of monoclonal antibodies displaying subnanomolar affinity to azoxystrobin was generated using, as immunizing haptens in mice, four functionalized derivatives carrying the same spacer arm located at different rationally chosen positions. This collection of antibodies was thoroughly characterized with homologous and hetero…
Benzodiazepines: specific competitors for the binding of L-tryptophan to human serum albumin.
1975
By means of the gel filtration technique, the effect of nine benzo-diazepine derivates on the binding of l-tryptophan to human serum albumin was investigated. Using equimolar tryptophan and benzodiazepine concentrations, all benzodiazepines with binding constants higher than 104 (M−1), displace l-tryptophan from its binding site to a high degree. The mechanism of the displacement was characterized as a competition for a common binding site. Some of the benzodiazepines displace l-tryptophan to a greater extent than salicylic acid. The benzodiazepines and tryptophan are the only substances known with a high degree of stereospecific binding to human serum albumin. This study shows that there i…
Identification of α2-adrenoceptors and non-adrenergic idazoxan binding sites in rabbit colon epithelial cells
1990
alpha 2-Adrenoceptors are possibly involved in the regulation of the hydroelectrolytic flux across the digestive mucosa. As no data are available concerning the existence of these receptors in colon epithelial cells, we aimed to investigate the existence of alpha 2-adrenoceptors in this tissue using tritiated antagonists. [3H]Yohimbine and [3H]rauwolscine were not usable to label colonic alpha 2-adrenoceptors because of their very high level of non-specific binding. In contrast, the methoxy derivative of idazoxan, [3H]RX821002, appeared a convenient radioligand for the purpose. [3H]RX821002 bound with high affinity (KD = 6.2 +/- 0.8 nM) to a single population of non-interacting sites (Bmax …
Effect of marathon characteristics and runners' time category on pacing profile.
2020
This study aimed to analyse differences in pacing profiles in four marathon competitions and to explore that pacing per time category. A database of 91,493 runners gathered from 4 different races was analysed (Valencia, Chicago, London and Tokyo Marathon). Participants were categorized in accordance with their completion time. The relative speed of each section for each runner was calculated as a percentage of the average speed for the entire race. In the four marathons studied, the first 5 km differed widely, presenting London the highest relative speeds (5 km: CI95% London vs. Valencia [12.1, 13.6%],
3H-cyproterone acetate: binding characteristics to human uterine progestagen receptors
1985
The availability of tritium labeled cyproterone acetate (CPA) facilitated the systematic investigation of the binding characteristics of this compound for human uterine progesterone receptors (PgR). The binding parameters of 3H-CPA are compared to those of 3H-R5020 and 3H-progesterone. The rate constants of association (k1M-1sec-1) to PgR were 7.8 X 10(3) for 3H-R5020, 4.5 X 10(4) for 3H-progesterone and 4.0 X 10(4) for 3H-CPA. The rate constants of dissociation (k-1, sec-1) were 3.6 X 10(-5) for 3H-R5020, 21.3 X 10(-5) for 3H-progesterone and 17.8 X 10(-5) for 3H-CPA. The Kd-values (M), as obtained by titration analysis and subsequent Scatchard plot analysis were 1.2 X 10(-9) for 3H-R5020,…
New Melanocortin 1 Receptor Binding Motif Based on the C-Terminal Sequence of ?-Melanocyte-Stimulating Hormone
2006
The C-terminal tripeptide of the alpha-melanocyte stimulating hormone (alpha-MSH11-13) possesses strong antiinflammatory activity without known cellular target. In order to better understand the structural requirements for function of such motif, we designed, synthesized and tested out Trp- and Tyr-containing analogues of the alpha-MSH11-13. Seven alpha-MSH11-13 analogues were synthesized and characterized for their binding to the melanocortin receptors recombinantly expressed in insect (Sf9) cells, infected with baculovirus carrying corresponding MC receptor DNA. We also tested these analogues on B16-F1 mouse melanoma cells endogenously expressing the MC1 receptor for binding and for abili…
Monitoring stress and recovery states: Structural and external stages of the short version of the RESTQ sport in elite swimmers before championships
2016
Background: Psychological stress and recovery monitoring is a key issue for increasing athletes' health, well-being, and performance. This multi-study report examined changes and the dose–response relationships between recovery–stress psychological states, training load (TL), heart rate (HR), heart rate recovery (HRR), and heart rate variability (HRV) while providing evidence for the factorial validity of a short French version of the Recovery–Stress Questionnaire for Athletes (RESTQ-36-R-Sport). Methods: Four hundred and seventy-three university athletes (Study 1), 72 full expert swimmers (Study 2), and 11 national to international swimmers (Study 3) participated in the study. Data were an…
Lack of binding of gestodene to estrogen receptor in human breast cancer tissue
1990
Competition studies with progesterone and estradiol receptors of human myometrial tissue as well as of mammary cancer tissue showed that gestodene bound with high affinity to the progesterone receptor, as did other synthetic and natural progestogens. However, gestodene did not bind to the estradiol receptor. The relative binding affinities of all tested synthetic and natural ligands showed no organ-specific differences and no differences between neoplastically transformed and normal tissues.