Cytori Therapeutics ( CYTX) Stock return since Jan. 1: 96% Cytori's base business of selling machines and related consumables that turn belly blubber into stem cell- enriched fat grafts for breast reconstruction and other soft tissue repair is hurting. While fourth-quarter results haven't been released yet, lower-than-expected sales in the third quarter and mounting losses offer little hope of a turnaround from what was a bad 2011. Simply put, Cytori is having trouble convincing doctors in Europe and Japan to buy their expensive stem-cell fat graft machines. And even when doctors do buy the device, they're not using it very much, or at all, because procedures aren't being reimbursed. (Most likely because Cytori has yet to provide convincing clinical data to prove that stem cell-enriched belly fat is superior in any way to "regular" fat.") The U.S. remains a closed market for Cytori because regulators here won't allow the company's machine to be sold without first demonstrating a real clinical benefit for patients. Meantime, Cytori continues to burn cash and raise money though dilutive stock sales in order to keep its unprofitable business afloat. Simultaneously, the company is funding large, expensive clinical trials in indications like heart repair following heart attack that will take years to fully enroll. Cytori shares closed Tuesday down 6% to $4.05.