Fc Glycosylation Characterization of Human Immunoglobulins G Using Immunocapture and LC-MS.

Immunoglobulins G (IgG) are proteins produced by the immune system of higher life forms that play a central role in the defense against microbial pathogens. IgG bind pathogens with the hypervariable Fab component and mediate a diversity of effector functions by binding to immune effector cells via their crystallizable (Fc) component. All IgG Fc carry a polymorphic N-glycan that regulates its binding properties and thereby its effector functions.

Isoniazid Bactericidal Activity Involves Electron Transport Chain Perturbation.

Accumulating evidence suggests that the bactericidal activity of some antibiotics may not be directly initiated by target inhibition. The activity of isoniazid (INH), a key first-line bactericidal antituberculosis drug currently known to inhibit mycolic acid synthesis, becomes extremely poor under stress conditions, such as hypoxia and starvation. This suggests that the target inhibition may not fully explain the bactericidal activity of the drug.

Liquid chromatography-electrochemical detection for the determination of ethoxyquin and its dimer in pear skin and salmon samples.

Ethoxyquin (EQ) is widely used as a synthetic antioxidant in animal feed, an antiscalding agent in apples and pears and as a color preservative in some spices. Since the presence of EQ in food products could cause negative health effects it is necessary to develop reliable analytical methods to evaluate the risk of human exposure. In this work, a sensitive, selective and accurate method based on solid-liquid extraction followed by clean-up with solid sorbent and liquid chromatography-electrochemical detection analysis with boron doped diamond electrode (LC-EC) for the determination of ethoxyquin and its dimer (EQDM) in pear skin and salmon samples, was developed.

Electrochemical Detectors in Liquid Chromatography: Recent Trends in Pharmaceutical and Biomedical Analysis.

Liquid chromatography (LC) coupled to an electrochemical (EC) detector is a complementary analytical tool compared to LC coupled with optical or mass spectrometry detectors (LC-MS). LC-EC can be applied to the determination of molecules difficult to be analyzed by other commercially available detectors. New EC detector design and new working electrode material have extended the scope of application in the field of pharmaceutical compounds analysis.

Contribution of Electrochemistry to the Biomedical and Pharmaceutical Analytical Sciences.

All analytical techniques have experienced major progress since the last ten years and electroanalysis is also involved in this trend. The unique characteristics of phenomena occurring at the electrode-solution interface along with the variety of electrochemical methods currently available allow for a broad spectrum of applications. Potentiometric, conductometric, voltammetric and amperometric methods are briefly reviewed with a critical view in terms of performance of the developed instrumentation with special emphasis on pharmaceutical and biomedical applications.

An experimental design approach to optimize an amperometric immunoassay on a screen printed electrode for Clostridium tetani antibody determination.

An immunoassay for the determination of anti-tetani antibodies has been developed using a screen printed electrode (SPE) as solid support for toxoid (antigen) immobilization. The assay was performed in guinea pig serum. The immunoreaction and the subsequent amperometric detection occurred directly onto the SPE surface.

Liquid Chromatography with Amperometric Detection at a Silver Based Detector for the Determination of Thiocompounds: Application to the Assay of Thiopurine Antimetabolites in Urine.

A silver amperometric detector coupled to liquid chromatography (LC) was used for the determination of 6-thioguanine (6-TG) and two of its metabolites, thiouric acid (TU) and 2-amino-6-mercaptopurine riboside (6-TGR). The silver detector coupled to LC operated at a low applied potential (0.08 V vs Ag/AgCl) and offered a chromatogram with peak responses corresponding to molecules interacting with silver, namely, chloride ions and small soluble biothiols in addition to the organothiol drug compounds investigated.

Flow-through enzyme immobilized amperometric detector for the rapid screening of acetylcholinesterase inhibitors by flow injection analysis.

A commercially available thin-layer flow-through amperometric detector, with the sensing block customized in an original design, was applied to the screening of drug compounds known as acetylcholinesterase (AChE) inhibitors. AChE from electric eel was covalently immobilized onto a cysteamine modified gold disk adjacent to a silver disk working electrode. On-line studies were performed by flow injection analysis (FIA) in PBS buffer pH 7.

Nanoimmunoassay onto a screen printed electrode for HER2 breast cancer biomarker determination.

A chip format sandwich-type immunoassay based on Nanobodies(®) (Nbs) with the Human Epidermal Growth Factor Receptor (HER2) extracellular domain as antigen model has been developed. The HER2 is considered as an important biomarker because its overexpression causes an aggressive type of breast cancer. Nbs are single domain antigen-binding fragments derived from camelid heavy-chain antibodies.