This invention relates to novel compounds suitable for labelling or already labelled by .sup.18F, methods of preparing such a compound, compositions comprising such compounds, kits comprising such compounds or compositions and uses of such compounds, compositions or kits for diagnostic imaging by positron emission tomography (PET).

Contemplated compounds, compositions, and methods are presented for use in the treatment, or prevention, of a cognitive, neurodegenerative or neuronal disorder or disease, such as Alzheimer's disease.

The invention disclosed herein discloses selected ribose isomers that are useful as PET probes (e.g. [18F]-2-fluoro-2-deoxy-arabinose). These PET probes are useful, for example, in methods designed to monitor physiological processes including ribose metabolism and/or to selectively observe certain tissue/organs in vivo. The invention disclosed herein further provides methods for making and using such probes.

A composition suitable for use as replacement material for all or part of a disc nucleus during percutaneous injection, the composition comprising: an injectable, curable, cross-linkable, non-immunogenic non-toxic protein hydrogel that (i) the protein component of the protein hydrogel contains at least one crosslinkable amino acid (ii) has a static compressive modulus of at least about 10 kPa, and (iii) has a dynamic compressive modulus of at least about 10 kPa; an iodinated contrast solution comprising an amount of an iodine compound sufficient to increase radiopacity to a discernable level, wherein the solution causes a decrease in the static and/or dynamic compressive modulus; and an amount of a crosslinker sufficient to restore at least about 100% of the decrease in static and/or dynamic compressive modulus caused by addition of the iodinated contrast solution.