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.
The rupture of an air sac in the outside of the lung may only cause pleurisy for a few days. But if a hidden pneumonia was the cause of the rupture, it may last much longer. And chronically diseased lungs, most commonly due to smoking, may rupture repeatedly and cause pleurisy to return again and again.