[Increased expression of the c-Met receptor mRNA in gastric cancer].

Gastric cancer is one of the most common malignancies in the world. In the last decades, the attention has been focused in possible alterations of genetic factors that include proto-oncogene activation and/or the tumor suppressor gene inactivation. The product of the proto-oncogene c-MET and its ligand, hepatocyte growth factor (HGF), have been implicated in cell proliferation and migration in gastric cancer.

Rapid analytical tryptic mapping of a recombinant chimeric monoclonal antibody and method validation challenges.

A rapid and reproducible analytical tryptic mapping method was developed as an identity test for a recombinant chimeric monoclonal antibody for lot release testing. The unfolding, reduction, carboxymethylation, trypsin digestion, and reversed-phase (RP) HPLC steps were optimized to provide a reproducible method. The optimized method requires 30 min for unfolding the protein, 30 min for carboxymethylation, 4 h for digestion with TPCK-trypsin and 140 min for RPHPLC analysis.

The role of assay validation in specification development.

Three of the main components that contribute to the establishment of specifications relate to manufacturing consistency, clinical experience, and assay performance. The validation of an analytical control system for biotechnology pharmaceutical products represents a diverse analytical challenge. This paper focusses on the key components of assay validation and how they influence specification design.

Quality control issues in the analysis of lyophilized proteins.

The assessment of protein stability requires the use of many sophisticated analytical techniques. Lyophilization procedures, commonly used to improve the stability profile of protein products, may potentiate undesirable protein degradation. The potential effects of lyophilization on proteins may include denaturation, decreased potency, aggregation, oxidation, and deamidation.