SCIENTISTS have created early stage sperm from the skin of men who cannot make their own, raising hopes of new treatments for currently incurable male infertility. A leading British expert said the stem cell research challenged the widely held view that the "door is closed" on men with the problem who want to have children. Although still at a very early stage, the study raises the future prospect of lab-grown sperm that could allow them to become fathers. Lead scientist Dr Reijo Pera, from...