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.
Conditions Involving the Pleural Cavity. The presence of an excess of fluid, or of air or gas in the pleural cavity can interfere with its function in respiration. Some conditions affecting the pleural space may include: Pleural effusion - A pleural effusion refers to a build-up of fluid in the pleural cavity.