By Issam AHMED Chinese scientists have succeeded in growing kidneys containing human cells in pig embryos, a world first that could one day help address organ donation shortages. But the development, described in a study in the journal Cell Stem Cell on Thursday, raises ethical issues — especially since some human cells were also found in the pigs’ brains, experts said. The researchers from the Guangzhou Institutes of Biomedicine and Health focused on kidneys because […]