Mixing species - and crossing a line?

TISSUES; HUMAN beings; ANIMALS; EMBRYONIC stem cells; STEM cells; GOLDSTEIN, Ronald; CELLS; BIOETHICS; RESEARCH ethics; BIOTECHNOLOGY; SCIENCE & ethics; BIOLOGY -- Social aspects; GENETIC engineering; ETHICS

Discusses the ethics of combining human and animal tissue. Work of Israeli scientist Ronald Goldstein implanting cells from human embryos into chicken eggs; Issue of crossing the species barriers by implanting stem cells in an animal; How concerns have transformed the debate over stem cells; Views of scientists on adding human embryonic cells to early mouse embryos; Arguments of bioethicists; Restrictions against stem-cell research in the U.S.; Why this kind of work is seen by some as problematic; Workshops on chimeric brains; Outlook.