TECH

SCIENTISTS DISCOVER THE SPEED OF DEATH

Scientists have just discovered what is being called the 'death rate' - and the way it acts resembles "falling dominoes," or fans doing "hello" in a crowded stadium.Observing death through a living cell for the first time, they found that their displacement velocity is 30 micrometers per minute.The way it behaves is very similar to a domino - one "death-inducing" molecule activates the other and that goes in succession, the new study discovered, until the cell dies.The study, conducted by the Stanford University School of Medicine, California, found that the cell dies in this 'cascade' effect.The phenomenon is observed in one of the most well-known forms of cell death - apoptosis, the researchers said.This normal and controlled situation occurs in multicellular organisms, such as humans and other animals.To study the speed of death, biologists James Ferrell and Xianrui Cheng removed the egg-stream from frogs and inserted them into test tubes.They then initiated apoptosis through a molecular "death sign."Using a fluorescent technique linked to the activation of cell death, they were able to observe at what constant rate the green light moved inside the tube.This indicated that apoptosis "spread like a wave," just like the swell of fans in a football game.It struck researchers that the process was visible to the naked eye: the frog's eggs are like huge single cells.Mr Ferrell, a biology and chemistry researcher at Stanford, said that this is yet another example of how waves are used by nature."Our study proves how nature behaves in waves," said one of the authors of the study. "The theme is recurrent in regulating cells."
He added, "Sometimes our cells die at times when we do not want them to die, like in neurodegenerative diseases, or in others they do not die when we want them to die, like cancer.
Post-doctor Mr Cheng was the author of the study, sponsored by the National Institutes of Health and published Friday by the journal Science.
According to Ferrel, the speed of death 'never slows', with increasing numbers of death molecules being converted into active particles
This happens, according to the scientist, incessantly and without losing the amplitude until "apoptosis is spread throughout the cell," he explained.
They further found that cell death "also propagates in intact cells."



Source:mirror.co.uk