Search results for "SERUM"
showing 10 items of 786 documents
THE RECOVERY-ELISA—A NOVEL ASSAY TECHNIQUE TO MONITOR THERAPY WITH HUMANIZED ANTIBODIES: THE EXAMPLE OF OMALIZUMAB
2013
The therapeutic use of antibodies has grown exponentially, providing new treatment options for various diseases. Monitoring treatment with therapeutic antibodies is a particular challenge because often the target antigen is no longer measurable or the results are unreliable. To overcome this problem, a recovery-ELISA was developed to quantify therapeutic antibody and antigen by a modification of the traditional sandwich immunoassay using omalizumab as an example. Standard serum samples were spiked with IgE and omalizumab in a certain concentration range to create standard curves. After incubation and washout procedures, the reaction was stopped and the plate read with bichromatic absorbance…
Chiral separation of oxprenolol by affinity electrokinetic chromatography-partial filling technique using human serum albumin as chiral selector
2005
The intrinsic characteristics of capillary electrophoresis have made this technique a powerful tool in the chiral separation field. The present paper deals with the enantiomeric separation of oxprenolol enantiomers by affinity electrokinetic chromatography-partial filling technique using human serum albumin (HSA) as chiral selector. Several experimental conditions and variables affecting the separation such as pH, HSA concentration and plug length, background electrolyte concentration, temperature and voltage were studied. Baseline separation of oxprenolol enantiomers was obtained in less than 8 min under the following selected conditions: electrophoretic buffer composed of 50 mM Tris-(hydr…
Evaluation of enantioselective binding of fluoxetine to human serum albumin by ultrafiltration and CE - Experimental design and quality considerations
2012
Several pharmacokinetic processes are affected by enantioselectivity (ES). At the level of distribution, protein binding (PB) is one of the most important. The enantioselective binding of fluoxetine (FLX) to HSA has been evaluated in this work by ultrafiltration of FLX–HSA mixtures and chiral analysis of unbound fractions by EKC-CD. PB, affinity constants (K) and ES were obtained for both enantiomers of FLX. In order to improve the consistency of the estimations, the evaluation of affinity constants of each enantiomer was performed using two designs, one keeping constant the total concentration of protein and varying the total concentration of the enantiomers, and the other in the opposite …
Evaluation of enantioselective binding of propanocaine to human serum albumin by ultrafiltration and electrokinetic chromatography under intermediate…
2011
Abstract Stereoselectivity in protein binding can have a significant effect on the pharmacokinetic and pharmacodynamic properties of chiral drugs. In this paper, the enantioselective binding of propanocaine (PRO) enantiomers to human serum albumin (HSA), the most relevant plasmatic protein in view of stereoselectivity, has been evaluated by incubation and ultrafiltration of racemic PRO–HSA mixtures and chiral analysis of the bound and unbound fractions by electrokinetic chromatography using HSA as chiral selector. Experimental conditions for the separation of PRO enantiomers using HSA as chiral selector and electrokinetic chromatography have been optimised. Affinity constants and protein bi…
Phase behavior of aqueous solutions of bovine serum albumin in the presence of dextran, at rest, and under shear.
2006
The demixing conditions for aqueous solutions of bovine serum albumin (BSA, fraction V) and for joint solutions of BSA plus dextran (DEX, M(w) = 2000 kg/mol) were determined by turbidimetric measurements as a function of composition, temperature, and shear rate. Aqueous solutions of BSA phase separate upon heating. Within the region of BSA concentrations between 0.05 and 32 wt %, the demixing temperature, T1, falls from ca. 65 degrees C to an almost constant value of 45 degrees C. Adding DEX to the BSA solutions reduces the homogeneous region of the mixture drastically where the amount of DEX required to lower T1 to 25 degrees C decreases rapidly as the concentration of BSA is raised. Exper…
Evidence for the presence of autoantibodies to the collagen-like portion of C1q in systemic lupus erythematosus.
1988
We investigated the connection between the C1q solid-phase binding assay (C1q SPBA) and double-stranded DNA antibodies, and analyzed the immune complex material in systemic lupus erythematosus (SLE) sera. Comparison with a new monoclonal assay for C1q-bearing immune complexes (the 242G3 assay) revealed that the immune complexes in SLE bind specifically to solid-phase C1q, and not to fluid-phase C1q. The C1q solid-phase binding activity sedimented as 7S IgG, was insensitive to DNase treatment, and could be selectively absorbed by C1q-coupled beads and by bovine serum albumin-anti-bovine serum albumin C1q beads, but not by DNA. Thus, antibodies to double-stranded DNA do not interfere in the C…
A Software Package for a Serum Bank Management
1979
A serum-bank is a collection of human serum samples coming from different locations (in our case Children Hospital, schools, factories, town departemens), allocated in some archives. Principal users of a such data-bank are, of course, physicians and biologists that are mainly interested in statistical analysis (computation of averages, variances factor analysis, etc.) of immunological and epidemiological relevance, in order to investigate about some haematochemical parameters common to some selected subset of the archives [1], [2].
Interacting processes in protein coagulation
1999
A strong interest is currently focused on protein self-association and deposit. This usually involves conformational changes of the entire protein or of a fragment. It can occur even at low concentrations and is responsible for pathologies such as systemic amyloidosis, Alzheimer's and Prion diseases, and other neurodegenerative pathologies. Readily available proteins, exhibiting at low concentration self-association properties related to conformational changes, offer very convenient model systems capable of providing insight into this class of problems. Here we report experiments on bovine serum albumin, showing that the process of conformational change of this protein towards an intermedia…
The Divergent Effect of Insulin-Like Growth Factor Binding Protein (IGFBP) - 1 on IGF-induced Steroidogenesis in Bovine Adrenocortical Cells is not d…
2007
In previous studies we have shown that insulin-like growth factor (IGF)-II stimulates basal as well as ACTH-induced cortisol secretion from bovine adrenocortical cells more potently than IGF-I. The steroidogenic effect of both, IGF-I and IGF-II, is mediated through the IGF-I receptor and modified by locally produced IGF binding proteins. Further studies demonstrate that bovine adrenocortical cells do synthesize IGFBP-1 to -4 and that their secretion is regulated differentially by IGFs and ACTH. Since IGFBP-1 selectively is induced 3- to 4- fold by ACTH, the aim of the following studies was to evaluate the effect of IGFBP-1 on IGF-induced cortisol secretion from bovine adrenocortical cells i…
Cylindrical Cuvette Light Refraction Measurements Technology to Analyse Biomedical Liquids
2015
Compact device of high sensitivity for measurement of the refractive indices for both stationary and flowing liquids has been developed. This device can be used to analyse a variety of biomedical liquids: urine, serum protein. The refractive index (RI) is determined by measuring the deviation of a laser beam passing through a cylindrical cuvette containing the test liquid. In order to significantly improve the resolution and stability of RI measurements, the repeated reflections and refractions of the light beam travelling through the cylindrical cuvette are employed.