AIDS kills because it attacks T helper cells – one of a group of cells called lymphocytes that are evolution’s most recent addition to our immune system. In the second of two supplements, the mysteries of the lymphocytes are unravelled
THE BITE of the king cobra kills its victims within two hours by paralysing the muscles of the heart andrespiratory system. Cobra venom is a cocktail of toxic substances, but the main ingredient is a neurotoxin – a peptide molecule that blocks messages from the nerves to the muscles. The victim dies unless injected with antivenin, which contains antibodies for the…
