Key to future stem cell production may lie inside the testicles

· Tissue is rich in formative cells, British scientists say · New source would avoid need to destroy embryos

Professor in drug study fraud claim

Psychiatrist says that he will fight charges of misconduct and defrauding the NHS.

Students to ask the public health minister to urgently tackle the growing rates of sexually transmitted infections in young people.

Alok Jha meets the scientist who wants to recruit half a million people for a controversial medical project.

Panel set up to combat medical research fraud calls on universities and NHS to view such misconduct as seriously as financial fraud.

· Chemist pooh-poohs 50th birthday celebrations · Reports of wonder drug also come in for criticism

John Sutherland meets a scientist who is confident we are approaching 'escape velocity' for defying ageing.