Magnetic resonance imaging (MRI) index and adipose mesenchymal stem cell (ADSC) number in transplanted mice. (A) MRI index in transplanted mice at 0 (pre-surgery), 3, 5 and 12 weeks after ADSC implant. Boxes refer to ADSC-implanted animals. *P <0.05, ADSC-implanted versus pre-surgery. The dotted line refers to placebo animals and represents the mean of all animals at different times after injection. ♦P <0.05, ADSC-implanted versus placebo. (B) Representative intervertebral disc histological section of ADSC positivity to anti-HuNu and counterstaining with Safranin-O at 12 weeks after transplant. Scale bar, 100 μm. (C) Correlation between ADSC number and MRI intensity index at 12 weeks after transplant. Cell number was counted in a circular region of one mm2 from a representative slide of disc slab. The point corresponding to zero ADSCs, represents the mean of placebo MRI values.