The genome of the organism that produces the world's most lethal toxin has been revealed. This toxin is the major weapon in the genome of Clostridium botulinum: less than two kg is enough to kill every person on the planet.
Tension pneumothorax: The most serious type of pneumothorax, this occurs when the pressure in the pleural space is greater than the atmospheric pressure, either because air becomes trapped in the pleural space or because the entering air is from a positive-pressure mechanical ventilator.
If air enters the pleural space either by a hole in the lung or the chest wall, the pressure in the pleural space equals the pressure outside the body. Thus, the vacuum is lost and the lung collapses. Spontaneous pneumothorax is caused by a rupture of a cyst or a small sac (bleb) on the surface of the lung.