Headline Jan 03, 2016/ ''' YEE HOW OLD ? '''

''' YEE HOW OLD ? '''

IMAGINE IF YOUR BODY  was in a constant state of renewal : recreating and reinventing itself........cell  by cell.

*Are you ready for this?*  

It largely does that now. In fact, if you averaged out the age of every cell in your body, you could well be no more than a ten.

That's the surprising news from a team of cell biologists working at the Karolinska Institute in Sweden. 

They have developed a technique for tracking the life cycle of individual human cells that will help us answer important questions about how our bodies function- When each cell is born, how fast it ages, and if and when it gets replaced. 

''If you are 30 years old, the average of your cell is not 30   -it may be half that or less,''  says 37 year old assistant professor Kirsty Spalding, who left Australia some years ago to study at Karolinska. 

In fact, scientists believe the  average age of all the cells in the adult can be as young as seven to ten years.

Scientists have long believed that the cells you're born with aren't  -for the most part  -the ones you have when you die. However, it's been hard to track how fast cells in various parts of the adult human get replaced.

The breakthrough came when the Swedish researchers realised the DNA in an individual cell carries within a hidden time capsule that, once unlocked, can reveal to within two years when that cell was formed.

The key to their discovery?   Above-ground nuclear testing in the '50s and early '60s, which resulted in large amounts of the naturally occurring readioactive  isotope  carbon-14  (C14}  being released into the atmosphere and incorporated in plants and animals.

Those levels dropped back dramatically once nuclear testing was halted in 1983, but continued to be monitored closely by scientists particularly in the northern hemisphere. 

The DNA of each cell comprises  30 per cent  carbon. When one cell divides to make a new cell, everything inside it is duplicated, including the DNA.

The carbon the cell uses to make this new  DNA  is derived from food. So the concentration of C14  in  DNA  parallels the level in the atmosphere at the time  DNA  was made  -as in other words, by measuring  C14 in cells, you can pinpoint when the cell was born.

Spalding and her colleagues first examined C14 levels in the growth rings of Swedish pine trees to work out a scale for the local population. 

Then they isolated cells from various body parts of cadavers of Swedish born before and after the nuclear tests. They found the average age of cells in the main body of the intestine of people in the mid-30s was 15.9 years.

*The muscles around the ribs of people in their late 30s had cells that were just 15.1 years old.New blood cells are constantly being turned over. 

*In fact, almost every part of our body is under continual renewal*.

The team was most interested in results on brain tissue, however. Spalding and her fellow researchers discovered all the neurons in the occipital of all the cerebral cortex [the part of the brain involved in processing visual information]-

Were almost as old as the individual, thus confirming a controversial theory that this part of the brain forms shortly after birth and is with us for life.

The Honour and Serving of the ''Operational Research''  continues. Thank Ya all for reading. And see you on the following one.

With respectful dedication to the Students, Professors and Teachers of the World. See Ya all on !WOW!   -the World Students Society:

''' Unseen Future '''

Good Night and God Bless

SAM Daily Times - the Voice of the Voiceless


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