Not so much a warning, but certainly bad news for Osiris. The mesenchymal stem cell drug Prochymal did not show efficacy in two large controlled study of graft versus host disease. ( Read that story here)

In more alarming news for at least some investors, Reuters is reporting that the US Securities and Exchange Commission has charged company CellCyte Genetics Corp has given false information to investors claiming that its stem cell technology was heading for human trials. Here’s more from Fierce Biotech

More seriously, a group called Bionet is calling for a clamp down on unregulated stem cell treatments, according to the BBC. The coalition of Chinese and European say patients are being subjected to a lot of hype and potential harm when they travel for these expensive treatments.

They are not the first:

See

Stick to the guidelines and fewer get hurt

Offshore stem cell therapies need sensitive regulation

Stem cell researchers face down stem cell tourism

On a philosophically lighter (though perhaps literally heavier note), mice fed the equivalent of the Atkins diet had fewer and less-active bone marrow and peripheral blood endothelial progenitor cells, compared to two other diet regimens. See the report in PNAS.

Here’s other work on how diet affects stem cells.