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.
Spontaneous pneumothorax is discussed elsewhere. Some patients with traumatic pneumothorax have an unsealed opening in the chest wall. When patients with an open pneumothorax inhale, the negative intrathoracic pressure generated by inspiration causes air to flow into the lungs through the trachea and simultaneously into the intrapleural space through the chest wall defect.