A. Papanastasiou-Diamandi

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The aim of this study was to determine the concentration and to evaluate the prognostic value of pepsinogen C (PepC) in breast cancer patients. PepC is an aspartic proteinase that is involved in the digestion of proteins in the stomach and is also synthesized by a subset of human breast tumors. PepC concentrations were measured with a highly sensitive(More)
Insulin-like growth factors (IGFs) are potent mitogens involved in the regulation of cell proliferation and apoptosis. The action of IGFs is mediated through a specific cell membrane receptor (IGF-IR), and the interactions between IGFs and this receptor are regulated by IGF-binding proteins (IGFBPs). IGFBP-3 is one such protein which either suppresses or(More)
Recent studies have suggested that insulin-like growth factors (IGFs) and insulin-like growth factor binding proteins (IGFBPs) may be implicated in the development and progression of breast cancer. Prostate-specific antigen (PSA), a serine protease, may play a role in the regulation of IGFs' function through cleavage of IGFBP-3, resulting in release of(More)
We describe a nonisotopic heterogeneous competitive immunoassay of digoxin in serum using either Fab fragments of a polyclonal antibody or a high-affinity monoclonal antibody. In the assay, digoxin competes with immobilized digoxin (digoxin:thyroglobulin conjugate) for binding to a biotinylated immunoreactant (Fab or monoclonal). The amount of biotinylated(More)
This new method for determining pancreatic isoamylase (EC 3.2.1.1) in serum involves two monoclonal antibodies: one immobilized in a microtitration well (the capture antibody), the other biotinylated. After the sample is incubated with the two antibodies, the captured immunocomplex is quantified by adding streptavidin labeled with a europium chelator and(More)
OBJECTIVE Development of an ultrasensitive immunoassay for serum PSA involving conventional detection probes. DESIGN AND METHODS The assay involves a polyclonal antibody immobilized in microtitration wells and a monoclonal antibody labeled with horseradish peroxidase. In a one-step assay, the enzymatic activity of the bound detection antibody is monitored(More)
Digoxin-like immunoreactive substances (DLIS) have been successfully extracted and concentrated from cord serum, mixed (cord and maternal) serum and placentas. Similar substances have also been extracted from normal adult serum, but DLIS in this medium are present in much lower concentrations. Concentrated DLIS have been separated into several(More)
The specificity of radioimmunoassay and fluorescence polarization immunoassay procedures for the measurement of digoxin has been assessed. Many steroids and lipids have been found to interfere and give false positive results for digoxin under the conditions of the study. Caution is recommended in the interpretation of digoxin measurements made by(More)
We evaluated the effect of hapten heterology on free thyroxine (FT4) immunoassays involving the biotin-streptavidin system and time-resolved fluorometry. We compared protein derivatives of thyroxine (T4) and triiodothyronine (T3) as solid-phase antigen or biotinylated protein-tracer conjugate for competitive (or sequential) binding to a mouse anti-T4(More)