Search results for "Assay"
showing 10 items of 2241 documents
Irreversible Inhibition of Epidermal Growth Factor Receptor Activity by 3-Aminopropanamides
2012
Irreversible epidermal growth factor receptor (EGFR) inhibitors contain a reactive warhead which covalently interacts with a conserved cysteine residue in the kinase domain. The acrylamide fragment, a commonly employed warhead, effectively alkylates Cys797 of EGFR, but its reactivity can cause rapid metabolic deactivation or nonspecific reactions with off-targets. We describe here a new series of irreversible inhibitors containing a 3-aminopropanamide linked in position 6 to 4-anilinoquinazoline or 4-anilinoquinoline-3- carbonitrile driving portions. Some of these compounds proved to be as efficient as their acrylamide analogues in inhibiting EGFR-TK (TK = tyrosine kinase) autophosphorylati…
Synthesis and biological activities of a new class of heat shock protein 90 inhibitors, designed by energy-based pharmacophore virtual screening
2013
The design through energy-based pharmacophore virtual screening has led to aminocyanopyridine derivatives as efficacious new inhibitors of Hsp90. The synthesized compounds showed a good affinity for the Hsp90 ATP binding site in the competitive binding assay. Moreover, they showed an excellent antiproliferative activity against a large number of human tumor cell lines. Further biological studies on the derivative with the higher EC50 confirmed its specific influence on the cellular pathways involving Hsp90.
Apoptotic effects of different drugs on cultured retinoblastoma Y79 cells
1998
This paper deals with the apoptotic effect exerted in human retinoblastoma Y79 cells by a number of compounds. A remarkable effect was observed after treatment with DNA-damaging agents, such as camptothecin, etoposide, cisplatin and carboplatin; camptothecin was found to be the most efficacious. Treatment with these compounds induced the appearance of morphological features of apoptosis in the cells together with the distinct fragmentation of DNA, as shown by agarose gel electrophoresis. These effects were also accompanied by a remarkable increase in the level of p53. Many other compounds, which are not DNA-damaging agents, induced the morphological features of apoptosis but none of them we…
The sea urchin embryo: a model to study Alzheimer's beta amyloid induced toxicity.
2009
Abstract Alzheimer’s disease (AD) is the most common form of dementia. The cause of AD is closely related to the accumulation of amyloid beta peptide in the neuritic plaques. The use of animal model systems represents a good strategy to elucidate the molecular mechanism behind the development of this pathology. Here we use the Paracentrotus lividus embryo to identify molecules and pathways that can be involved in the degenerative process. As a first step, we identified the presence of an antigen related to the human APP, called Pl APP. This antigen, after gastrula stage, is processed producing a polypeptide of about 10 kDa. By immunohistochemistry we localized the Pl APP antigen in some ser…
Mepanipyrim haptens and antibodies with nanomolar affinity
2013
Mepanipyrim is an anilinopyrimidine fungicide used worldwide for crop protection. With the aim of developing useful immunoreagents for mepanipyrim immunoanalysis, two new functionalized derivatives were prepared and antibodies were generated. Affinity and specificity were assessed by direct and indirect competitive ELISA using homologous and heterologous conjugates. Although all antibodies were selective for the target analyte, the immunizing hapten structure was revealed as a determinant for high-affinity antibody production (IC50 = 3 nM). © 2013 The Royal Society of Chemistry.
Ready Access to Proquinazid Haptens via Cross-Coupling Chemistry for Antibody Generation and Immunoassay Development.
2015
17 pages, 4 tables, 5 figures.-- Publisher's PDF
Sub- and supercritical fluid extraction of trichloropyridinol from soil prior to immunoassay
1997
A comparative study on the extraction of TCP (3,5,6-trichloro-2-pyridinol, a metabolite of chlorpyrifos) from soil with CO2 and H2O is reported. The polarity of the analyte requires the presence of both a cosolvent (methanol) and an ion-pair reagent [(1R)-(-)-10-camphorsulfonic acid ammonium salt] for 95% extraction in 30 min when supercritical CO2 at 40 degrees C and 383 bar is used as extractant. Subcritical water (250 degrees C and 200 bar) enables complete extraction within 15 min without additives. Quantitation of the target analyte is performed by specific immunoassay using a non-commercial monoclonal antibody which provides a linear determination range between 0.005 and 5 micrograms/…
Exploring alternative hapten tethering sites for high-affinity anti-picoxystrobin antibody generation
2011
The relevance of the linker tethering site in haptens was investigated for antibody generation and immunoassay development. Three derivatives of the strobilurin fungicide picoxystrobin were synthesized with the same functionalized spacer arm located at three different positions. Protein conjugates of those haptens were employed as immunogens, and novel polyclonal antibodies were produced and characterized. All haptens afforded highly specific antibodies, but different affinities to the free analyte were observed among the obtained antisera. Next, competitive enzyme-linked immunosorbent assays were studied in several formats, and site heterology was confirmed as an effective strategy for det…
Assessment of oxidative damage to proteins and DNA in urine of newborn infants by a validated UPLC-MS/MS approach
2014
The assessment of oxidative stress is highly relevant in clinical Perinatology as it is associated to adverse outcomes in newborn infants. This study summarizes results from the validation of an Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous quantification of the urinary concentrations of a set of endogenous biomarkers, capable to provide a valid snapshot of the oxidative stress status applicable in human clinical trials, especially in the field of Perinatology. The set of analytes included are phenylalanine (Phe), para-tyrosine (p-Tyr), ortho-tyrosine (o-Tyr), meta-tyrosine (m-Tyr), 3-NO2-tyrosine (3NO(2)-Tyr), 3-Cl-tyrosine (3Cl-T…
Rapid assay of resveratrol in red wine by paper spray tandem mass spectrometry and isotope dilution.
2017
A rapid analytical approach for the assay of resveratrol in red wines, based on Paper Spray Mass Spectrometry (PS-MS) and Multiple Reaction Monitoring (MRM) is described. The assay involves the use of the stable isotope dilution method. The analytical parameters calculated analyzing fortified samples confirm the reliability of the proposed approach, with accuracy values about 100%, and LOD and LOQ values calculated at 0.5 and 0.8 μg/mL, respectively. Furthermore, both the recovery, which was quantitative for the analyte, and the reproducibility (RSD%), checked on different days on the same wine, always below 7%, highlighted the consistency of the methodology.