Abstract: The present application presents a method of assessing a predisposition to osteonecrosis in an individual based on the level of expression/activity of alpha-2-macroglubulin, a biomarker whose expression is positively correlated with osteonecrosis. Also provided herein are a diagnostic/prognostic system as well as a software product based on the determination of the level of expression/activity of alpha-2-macroglobulin. Screening methods for the determination of usefulness of an agent in the prevention and/or treatment of osteonecrosis are also provided.

Abstract: The present invention relates to a DNA sequence for the human cytidine deaminase that has been engineered into an eukaryotic expression vector, thereby permitting cytidine deaminase expression in mammalian cells. Cytidine deaminase expression confers resistance to cytosine nucleoside analogs, such as cytosine arabinoside, and can be used as a positive selectable marker. The expression of cytidine deaminase in cells protects them from the toxic effects of cytosine nucleoside analogs. Such a resistance provides applications for gene therapy of malignant, immune and viral diseases. A bacterial expression vector containing the gene can be used to produce cytidine deaminase in large quantities.