Cell Transplantation and “Stem Cell Therapy” in the Treatment of Myopathies: Many Promises in Mice, Few Realities in Humans

Figure 9

Ischemic necrosis in an intramuscular accumulation of grafted myoblasts one day after their transplantation in the skeletal muscle of a nonhuman primate. Arrowheads in (A) circumscribe the intramuscular accumulation of grafted cells in a section stained with hematoxylin and eosin (H and E). Two regions with different staining characteristics can be observed in this cell pocket: a darker peripheral ring (a) and a paler core (b). In a serial section (B) stained for the histochemical detection of the oxidative enzyme nicotinamide adenine dinucleotide reduced diaphorase (NADH), the two regions are more clearly delimitated: a peripheral ring strongly stained ((a): living cells with oxidative activity) and a central region almost devoid of oxidative reaction ((b): necrosed cells with few or no oxidative activity). A detail of this pocket of grafted cells (rectangle in (A)) is shown at higher magnification in (C). In (C), the peripheral layer (a) is composed of cells with normal characteristics, while the core (b) has smaller cells with pyknosis, karyorrhexis, and in several cases loss of cytoplasmic staining. Scale bars: 200 μm ((A) and (B)) and 50 μm (C).