Transplantation of stem cells has the possibility of restoring neural functions after stroke damage. Therefore, we transplanted neuronal progenitors generated from monkey embryonic stem (ES) cells into the ischemic mouse brain to test this possibility. Monkey ES cells were caused to differentiate into neuronal progenitors by the stromal cell-derived inducing activity method. Focal cerebral ischemia was induced by occluding the middle cerebral artery by the intraluminal filament technique. The donor cells were transplanted into the ischemic lateral striatum at 24 h after the start of reperfusion. The cells transplanted into the ischemic brain became located widely around the ischemic area, and, moreover, the transplanted cells differentiated into various types of neurons and glial cells. Furthermore, at 28 days after the transplantation, over 10 times more cells in the graft were labeled with Fluorogold (FG) by stereotactic focal injection of FG into the anterior thalamus and substantia nigra on the grafted side when compared with the number at 14 days. From these results we confirmed the survival and differentiation of, as well as network formation by, monkey ES-cell-derived neuronal progenitors transplanted into the ischemic mouse brain.

The authors confirmed the survival and differentiation of ESC-derived NPCs transplanted into the ischemic brain. Surviving transplanted cells expressed several neural markers and neurotransmitters. These findings indicate that these cells can function in the brain.

Our results indicate that the MCA specimens from MMD patients had thicker intimal walls than the specimens from control patients. In addition, hypoxia-inducing factor-1alpha and endoglin were overexpressed in the intima of the MCA of MMD patients.

In the evaluation of patient satisfaction as an outcome in patients operated on for degenerative lumbar spinal stenosis, we should keep in mind that postoperative functioning is a weak correlate of satisfaction.