Sportsmen and women dope with the blood hormone Epo to enhance their performance. Researchers from the University of Zurich now discovered by animal testing that Epo has a performance-enhancing effect in the brain shortly after injection and not only after days by improving oxygen transport in blood. As Epo also increases motivation, it could be useful in treating depression.

In April 2009, the world took notice as reports surfaced of a virus in Mexico that had mutated from pigs and was being passed from human to human. The H1N1 "swine flu," as the virus was named, circulated worldwide, killing more than 18,000 people, according to the World Health Organization. The Centers for Disease Control and Prevention in the United States said it was the first global pandemic in more than four decades.

The rare ability of some individuals to control HIV infection with their immune system alone appears to depend – at least partially – on specific qualities of the immune system's killer T cells and not on how many of those cells are produced. In a Nature Immunology paper that has received advance online publication, researchers at the Ragon Institute of Massachusetts General Hospital, MIT and Harvard report that – even among individuals sharing a protective version of an important immune system molecule – the ability of HIV-specific killer T cells to control viral replication appears to depend on the particular sequence of the protein that recognizes HIV infected cells.

Bacteria are omnipresent – in the water, the air and the soil, as well as in plants, animals and even people. We tend to think of bacteria as pathogenic, causing disease. We associate them with intestinal upsets and throat infections, pneumonia and blood poisoning. However, the great majority of bacteria are really useful – they play a role in our digestion, clean up waste water in sewage treatment plants, produce yoghurt and cheese from milk, and some are even used in the manufacture of drugs.